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[bug#56046] services: mail: add opensmtpd records to enhance opensmtpd-configuration.

Message ID 20220617214618.12377-1-jbranso@dismail.de
State New
Headers show
Series [bug#56046] services: mail: add opensmtpd records to enhance opensmtpd-configuration. | expand

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Commit Message

Joshua Branson June 17, 2022, 9:46 p.m. UTC
Openmstpd-configuration may only be configured by a config-file.  This
patch, enables one to configure opensmtpd by using some guile record
types (defined via define-record-type*).

This patch is mostly complete, but I could use some guidance on what
else needs to be done for it to be accepted in to guix properly.
I do have some documentation written for the opensmtpd-service,
but it is probably not complete and is currently written in the
org-mode format.                     

* gnu/services/mail.scm (opensmtpd-table-configuration): New record.
* gnu/services/mail.scm (opensmtpd-ca-configuration): New record.
* gnu/services/mail.scm (opensmtpd-pki-configuration): New record.
* gnu/services/mail.scm (opensmtpd-action-local-delivery-configuration): New record.
* gnu/services/mail.scm (opensmtpd-maildir-configuration): New record.
* gnu/services/mail.scm (opensmtpd-mda-configuration): New record.
* gnu/services/mail.scm (opensmtpd-action-relay-configuration): New record.
* gnu/services/mail.scm (opensmtpd-option-configuration): New record.
* gnu/services/mail.scm (opensmtpd-filter-phase-configuration): New record.
* gnu/services/mail.scm (opensmtpd-filter-configuration): New record.
* gnu/services/mail.scm (opensmtpd-listen-on-configuration): New record.
* gnu/services/mail.scm (opensmtpd-listen-on-socket-configuration): New record.
* gnu/services/mail.scm (opensmtpd-match-configuration): New record.
* gnu/services/mail.scm (opensmtpd-smtp-configuration): New record.
* gnu/services/mail.scm (opensmtpd-srs-configuration): New record.
* gnu/services/mail.scm (opensmtpd-queue-configuration): New record.
* gnu/services/mail.scm (opensmtpd-configuration): New record.
---
 gnu/services/mail.scm | 2016 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 2013 insertions(+), 3 deletions(-)

Comments

ashish.is--- via Guix-patches" via July 5, 2022, 9:36 p.m. UTC | #1
Here is a video link that may help the first reviewer:

https://video.hardlimit.com/w/ixE7Tc1pCqpP3BgriRbYA5 (https://video.hardlimit.com/w/ixE7Tc1pCqpP3BgriRbYA5)
The video walks you through how to play with an example configuration in emacs-geiser.

Thanks,

Joshua
Vivien Kraus June 15, 2023, 4:06 p.m. UTC | #2
Hello guix,

I would very much like to have better support (more modular) for
opensmtpd. This patch series seems to go in the right direction. What
is its status?

Best regards,

Vivien
Joshua Branson Aug. 18, 2023, 11:16 a.m. UTC | #3
Vivien Kraus <vivien@planete-kraus.eu> writes:

> Hello guix,
>
> I would very much like to have better support (more modular) for
> opensmtpd. This patch series seems to go in the right direction. What
> is its status?
>
> Best regards,
>
> Vivien

So, I recently just got my email server up and running again, which is
awesome!  What is its status?

It works!  You can configure fairly basic email configurations.  You
should try to run it on your server.  This blog post walks you through how:

https://gnucode.me/submitting-opensmtpd-service-to-guixrus.html

You might not be able to use guix deploy with this service at the
moment.  You might have to ssh into your server and do a "guix system
reconfigure".  I fixed that bug, but have not pushed it to guixrus yet.

Feel free to ask me any questions.

In terms of upstreaming this to guix proper.  It seems like I should
* convert all of the (define-record-type* ...) -> (define-configuration)
* make sure all of the tests still work:
https://notabug.org/jbranso/guix/src/newOpensmtpdBranch/gnu/tests/mail.scm
* try to generate Tobias' smtpd.conf
* host a guix system is awesome party


There's a ton more in the task here:
https://notabug.org/jbranso/linode-guix-system-configuration/src/master/opensmtpd.org

Joshua
diff mbox series

Patch

diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
index d99743ac31..bdc0ee3bf7 100644
--- a/gnu/services/mail.scm
+++ b/gnu/services/mail.scm
@@ -57,8 +57,143 @@  (define-module (gnu services mail)
             mailbox-configuration
             namespace-configuration
 
+            opensmtpd-table-configuration
+            opensmtpd-table-configuration?
+            opensmtpd-table-configuration-name
+            opensmtpd-table-configuration-file-db
+            opensmtpd-table-configuration-data
+
+            opensmtpd-ca-configuration
+            opensmtpd-ca-configuration?
+            opensmtpd-ca-configuration-name
+            opensmtpd-ca-configuration-file
+
+            opensmtpd-pki-configuration
+            opensmtpd-pki-configuration?
+            opensmtpd-pki-configuration-domain
+            opensmtpd-pki-configuration-cert
+            opensmtpd-pki-configuration-key
+            opensmtpd-pki-configuration-dhe
+
+            opensmtpd-action-local-delivery-configuration
+            opensmtpd-action-local-delivery-configuration?
+            opensmtpd-action-local-delivery-configuration-method
+            opensmtpd-action-local-delivery-configuration-alias
+            opensmtpd-action-local-delivery-configuration-ttl
+            opensmtpd-action-local-delivery-configuration-user
+            opensmtpd-action-local-delivery-configuration-userbase
+            opensmtpd-action-local-delivery-configuration-virtual
+            opensmtpd-action-local-delivery-configuration-wrapper
+
+            opensmtpd-maildir-configuration
+            opensmtpd-maildir-configuration?
+            opensmtpd-maildir-configuration-pathname
+            opensmtpd-maildir-configuration-junk
+
+            opensmtpd-mda-configuration
+            opensmtpd-mda-configuration-name
+            opensmtpd-mda-configuration-command
+
+            opensmtpd-action-relay-configuration
+            opensmtpd-action-relay-configuration?
+            opensmtpd-action-relay-configuration-backup
+            opensmtpd-action-relay-configuration-backup-mx
+            opensmtpd-action-relay-configuration-helo
+            opensmtpd-action-relay-configuration-domain
+            opensmtpd-action-relay-configuration-host
+            opensmtpd-action-relay-configuration-pki
+            opensmtpd-action-relay-configuration-srs
+            opensmtpd-action-relay-configuration-tls
+            opensmtpd-action-relay-configuration-auth
+            opensmtpd-action-relay-configuration-mail-from
+            opensmtpd-action-relay-configuration-src
+
+            opensmtpd-option-configuration
+            opensmtpd-option-configuration?
+            opensmtpd-option-configuration-option
+            opensmtpd-option-configuration-not
+            opensmtpd-option-configuration-regex
+            opensmtpd-option-configuration-data
+
+            opensmtpd-filter-phase-configuration
+            opensmtpd-filter-phase-configuration?
+            opensmtpd-filter-phase-configuration-name
+            opensmtpd-filter-phase-configuration-phase-name
+            opensmtpd-filter-phase-configuration-options
+            opensmtpd-filter-phase-configuration-decision
+            opensmtpd-filter-phase-configuration-message
+            opensmtpd-filter-phase-configuration-value
+
+            opensmtpd-filter-configuration
+            opensmtpd-filter-configuration?
+            opensmtpd-filter-configuration-name
+            opensmtpd-filter-configuration-proc
+
+            opensmtpd-listen-on-configuration
+            opensmtpd-listen-on-configuration?
+            opensmtpd-listen-on-configuration-interface
+            opensmtpd-listen-on-configuration-family
+            opensmtpd-listen-on-configuration-auth
+            opensmtpd-listen-on-configuration-auth-optional
+            opensmtpd-listen-on-configuration-filters
+            opensmtpd-listen-on-configuration-hostname
+            opensmtpd-listen-on-configuration-hostnames
+            opensmtpd-listen-on-configuration-mask-src
+            opensmtpd-listen-on-configuration-disable-dsn
+            opensmtpd-listen-on-configuration-pki
+            opensmtpd-listen-on-configuration-port
+            opensmtpd-listen-on-configuration-proxy-v2
+            opensmtpd-listen-on-configuration-received-auth
+            opensmtpd-listen-on-configuration-senders
+            opensmtpd-listen-on-configuration-secure-connection
+            opensmtpd-listen-on-configuration-tag
+
+            opensmtpd-listen-on-socket-configuration
+            opensmtpd-listen-on-socket-configuration?
+            opensmtpd-listen-on-socket-configuration-filters
+            opensmtpd-listen-on-socket-configuration-mask-src
+            opensmtpd-listen-on-socket-configuration-tag
+
+            opensmtpd-match-configuration
+            opensmtpd-match-configuration?
+            opensmtpd-match-configuration-action
+            opensmtpd-match-configuration-options
+
+            opensmtpd-smtp-configuration
+            opensmtpd-smtp-configuration?
+            opensmtpd-smtp-configuration-ciphers
+            opensmtpd-smtp-configuration-limit-max-mails
+            opensmtpd-smtp-configuration-limit-max-rcpt
+            opensmtpd-smtp-configuration-max-message-size
+            opensmtpd-smtp-configuration-sub-addr-delim character
+
+            opensmtpd-srs-configuration
+            opensmtpd-srs-configuration?
+            opensmtpd-srs-configuration-key
+            opensmtpd-srs-configuration-backup-key
+            opensmtpd-srs-configuration-ttl-delay
+
+            opensmtpd-queue-configuration
+            opensmtpd-queue-configuration?
+            opensmtpd-queue-configuration-compression
+            opensmtpd-queue-configuration-encryption
+            opensmtpd-queue-configuration-ttl-delay
+
             opensmtpd-configuration
             opensmtpd-configuration?
+            opensmtpd-package
+            opensmtpd-config-file
+            opensmtpd-configuration-bounce
+            opensmtpd-configuration-listen-ons
+            opensmtpd-configuration-listen-on-socket
+            opensmtpd-configuration-includes
+            opensmtpd-configuration-matches
+            opensmtpd-configuration-mda-wrappers
+            opensmtpd-configuration-mta-max-deferred
+            opensmtpd-configuration-srs
+            opensmtpd-configuration-smtp
+            opensmtpd-configuration-queue
+
             opensmtpd-service-type
             %default-opensmtpd-config-file
 
@@ -1651,13 +1786,1888 @@  (define (generate-dovecot-documentation)
 ;;; OpenSMTPD.
 ;;;
 
+;; some fieldnames have a default value of #f, which is ok.  They cannot have a value of #t.
+;; for example opensmtpd-table-configuration-data can be #f, BUT NOT true.
+;; my/sanitize procedure tests values to see if they are of the right kind.
+;; procedure false? is needed to allow fields like 'values' to be blank, (empty), or #f BUT also
+;; have a value like a list of strings.
+(define (false? var)
+  (eq? #f var))
+
+;; this procedure takes in a var and a list of procedures.  It loops through list of procedures passing in var to each.
+;; if one procedure returns #t, the function returns true.  Otherwise #f.
+;; TODO for fun rewrite this using map
+;; If I rewrote it in map, then it may help with sanitizing.
+;; eg: I could then potentially easily sanitize vars with lambda procedures.
+(define (is-value-right-type? var list-of-procedures record fieldname)
+  (if (null? list-of-procedures)
+        #f
+        (cond [(procedure? (car list-of-procedures))
+               (if ((car list-of-procedures) var)
+                   #t
+                   (is-value-right-type? var (cdr list-of-procedures) record fieldname))]
+              [(and (sanitize-configuration? (car list-of-procedures))
+                    (sanitize-configuration-error-if-proc-fails (car list-of-procedures))
+                    (if ((sanitize-configuration-proc (car list-of-procedures)) var)
+                        #t
+                        (begin
+                          (apply string-append
+                                 (sanitize-configuration-error-message (car list-of-procedures)))
+                          (throw 'bad! var))))]
+              [else (if ((sanitize-configuration-proc (car list-of-procedures)) var)
+                        #t
+                        (is-value-right-type? var (cdr list-of-procedures) record fieldname))])))
+
+;; converts strings like this:
+;; "apple, ham, cherry" -> "apple, ham, or cherry"
+;; "pineapple" -> "pinneapple".
+;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
+(define (add-comma-or string)
+  (define last-comma-location (string-rindex string #\,))
+  (if last-comma-location
+      (if (string-contains string ", or" last-comma-location)
+          string
+          (string-replace string ", or" last-comma-location
+                          (+ 1 last-comma-location)))
+      string))
+
+;; I could test for read-ability of a file, but then I would have to
+;; test the program as root everytime instead of as a normal user...
+(define (file-exists? file)
+(if (string? file)
+    (access? file F_OK)
+    #f))
+
+(define (list-of-procedures->string procedures)
+  (define string
+    (let loop ([procedures procedures])
+      (if (null? procedures)
+          ""
+          (begin
+            (string-append
+             (cond [(eq? false? (car procedures))
+                    "#f , "]
+                   [(eq? boolean? (car procedures))
+                    "boolean, "]
+                   [(eq? string? (car procedures))
+                    "string, "]
+                   [(eq? integer? (car procedures))
+                    "integer, "]
+                   [(eq? list-of-strings? (car procedures))
+                    "list of strings, "]
+                   [(eq? assoc-list? (car procedures))
+                    "an association list, "]
+                   [(eq? opensmtpd-pki-configuration? (car procedures))
+                    "an <opensmtpd-pki-configuration> record, "]
+                   [(eq? opensmtpd-table-configuration? (car procedures))
+                    "an <opensmtpd-table-configuration> record, "]
+                   [(eq? list-of-unique-opensmtpd-match-configuration? (car procedures))
+                    "a list of unique <opensmtpd-match-configuration> records, "]
+                   [(eq? table-whose-data-are-assoc-list? (car procedures))
+                    (string-append
+                    "an <opensmtpd-table-configuration> record whose fieldname 'values' are an assoc-list \n"
+                    "(eg: (opensmtpd-table-configuration (name \"table\") (data '(\"joshua\" . \"$encrypted$password\")))), ")]
+                   [(eq? file-exists? (car procedures))
+                    "file, "]
+                   [else "has an incorrect value, "])
+             (loop (cdr procedures)))))))
+  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
+
+;; TODO can I M-x raise-sexp (string=? string var) in this procedure? and get rid of checking
+;; if the var is a string?  The previous string-in-list? had that check.
+;; (string-in-list? '("hello" 5 "cat")) currently works.  If I M-x raise-sexp (string=? string var)
+;; then it will no longer work.
+(define (string-in-list? string list)
+  (primitive-eval (cons 'or (map (lambda (var) (and (string? var) (string=? string var))) list))))
+
+(define (my/sanitize var record fieldname list-of-procedures)
+  (if (is-value-right-type? var list-of-procedures record fieldname)
+      var
+      (begin
+        (display (string-append "<" record "> fieldname: '" fieldname "' is of type "
+                                (list-of-procedures->string list-of-procedures) "\n"))
+        (throw 'bad! var))))
+
+;; Some example opensmtpd-table-configurations:
+;;
+;;  (opensmtpd-table-configuration (name "root accounts") (data '(("joshua" . "root@dismail.de") ("joshua" . "postmaster@dismail.de"))))
+;;  (opensmtpd-table-configuration (name "root accounts") (data (list "mysite.me" "your-site.com")))
+;;  TODO should <opensmtpd-table-configuration> support have a fieldname 'file'?
+;;  Or should I change name to name-or-file ?
+(define-record-type* <opensmtpd-table-configuration>
+  opensmtpd-table-configuration make-opensmtpd-table-configuration
+  opensmtpd-table-configuration?
+  this-record
+  (name opensmtpd-table-configuration-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-table-configuration" "name" (list string?)))))
+  (file-db opensmtpd-table-configuration-file-db
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-table-configuration" "file-db"
+                                    (list boolean?)))))
+  ;; FIXME support an aliasing table as described here:
+  ;; https://man.openbsd.org/table.5
+  ;; One may have to use the record file for this.  I don't think tables support a table like this:
+  ;; table "name" { joshua = joshua@gnucode.me,joshua@gnu-hurd.com,joshua@propernaming.org, root = root@gnucode.me }
+  ;; If values is an absolute filename, then it will use said filename to house the table info.
+  ;; filename must be an absolute filename.
+  (data opensmtpd-table-configuration-data
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-table-configuration" "values"
+                                   (list file-exists? list-of-strings? assoc-list?)))))
+  ;; is a list of values or key values
+  ;; eg: (list "mysite.me" "your-site.com")
+  ;; eg: (list ("joshua" . "joshua@gnu.org") ("james" . "james@gnu.org"))
+  ;; I am currently making these values be as assocation list of strings only.
+  ;; FIXME should I allow a var like this?
+  ;; (list (cons "gnucode.me" 234.949.392.23))
+  ;; can be of type: (quote list-of-strings) or (quote assoc-list)
+  ;; (opensmtpd-table-configuration-type record) returns the values' type.  The user SHOULD NEVER set the type.
+  ;; TODO jpoiret: on irc reccomends that I just use an outside function to determine fieldname 'values', type.
+  ;; it would be "simpler" and possibly easier for the next person working on this code to understand what is happening.
+  (type opensmtpd-table-configuration-type
+        (default #f)
+        (thunked)
+        (sanitize (lambda (var)
+                    (cond [(opensmtpd-table-configuration-data this-record)
+                           (if (list-of-strings? (opensmtpd-table-configuration-data this-record))
+                               (quote list-of-strings)
+                               (quote assoc-list))]
+                          [(file-exists? (opensmtpd-table-configuration-data this-record))
+                           (if (opensmtpd-table-configuration-file-db this-record)
+                               (quote db)
+                               (quote file))]
+                          [else
+                           (display "opensmtpd-table-configuration-type is broke\n")
+                           (throw 'bad! var)])))))
+
+(define-record-type* <opensmtpd-ca-configuration>
+  opensmtpd-ca-configuration make-opensmtpd-ca-configuration
+  opensmtpd-ca-configuration?
+  (name opensmtpd-ca-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca-configuration" "name" (list string?)))))
+  (file opensmtpd-ca-configuration-file
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca-configuration" "file" (list file-exists?))))))
+
+(define-record-type* <opensmtpd-pki-configuration>
+  opensmtpd-pki-configuration make-opensmtpd-pki-configuration
+  opensmtpd-pki-configuration?
+  (domain opensmtpd-pki-configuration-domain
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-pki-configuration" "domain" (list string?)))))
+  ;; TODO/FIXME this should probably be a list of files.  The opensmtpd documentation says
+  ;; that you could have a list of files:
+  ;;
+  ;; pki pkiname cert certfile
+  ;; Associate certificate file certfile with host pkiname, and use that file to prove
+  ;; the identity of the mail server to clients.  pkiname is the server's name, de‐
+  ;; rived from the default hostname or set using either
+  ;; /gnu/store/2d13sdz76ldq8zgwv4wif0zx7hkr3mh2-opensmtpd-6.8.0p2/etc/mailname or us‐
+  ;; ing the hostname directive.  If a fallback certificate or SNI is wanted, the ‘*’
+  ;; wildcard may be used as pkiname.
+
+  ;; A certificate chain may be created by appending one or many certificates, includ‐
+  ;; ing a Certificate Authority certificate, to certfile.  The creation of certifi‐
+  ;; cates is documented in starttls(8).
+  (cert opensmtpd-pki-configuration-cert
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-pki-configuration" "cert" (list file-exists?)))))
+  (key opensmtpd-pki-configuration-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-pki-configuration" "key" (list file-exists?)))))
+  ; todo sanitize this. valid parameters are "none", "legacy", or "auto".
+  (dhe opensmtpd-pki-configuration-dhe
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-dhe" "dhe" (list false? string?))))))
+
+(define-record-type* <opensmtpd-lmtp-configuration>
+  opensmtpd-lmtp-configuration make-opensmtpd-lmtp-configuration
+  opensmtpd-lmtp-configuration?
+  (destination opensmtpd-lmtp-configuration-destination
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-lmtp-configuration" "destination"
+                                        (list string?)))))
+  (rcpt-to opensmtpd-lmtp-configuration-rcpt-to
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-lmtp-configuration" "rcpt-to"
+                                    (list false? string?))))))
+
+(define-record-type* <opensmtpd-mda-configuration>
+  opensmtpd-mda-configuration make-opensmtpd-mda-configuration
+  opensmtpd-mda-configuration?
+  (name opensmtpd-mda-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-mda-configuration" "name"
+                                 (list string?)))))
+  ;; TODO should I allow this command to be a gexp?
+  (command opensmtpd-mda-configuration-command
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-mda-configuration" "command"
+                                    (list string?))))))
+
+(define-record-type* <opensmtpd-maildir-configuration>
+  opensmtpd-maildir-configuration make-opensmtpd-maildir-configuration
+  opensmtpd-maildir-configuration?
+  (pathname opensmtpd-maildir-configuration-pathname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-maildir-configuration" "pathname"
+                                     (list false? string?)))))
+  (junk opensmtpd-maildir-configuration-junk
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-maildir-configuration" "junk"
+                                 (list boolean?))))))
+
+(define-record-type* <opensmtpd-action-local-delivery-configuration>
+  opensmtpd-action-local-delivery-configuration make-opensmtpd-action-local-delivery-configuration
+  opensmtpd-action-local-delivery-configuration?
+  (name opensmtpd-action-local-delivery-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-local-delivery-configuration" "name"
+                                 (list string?)))))
+  (method opensmtpd-action-local-delivery-configuration-method
+          (default "mbox")
+          (sanitize (lambda (var)
+                      (cond
+                       [(or (opensmtpd-lmtp-configuration? var)
+                            (opensmtpd-maildir-configuration? var)
+                            (opensmtpd-mda-configuration? var)
+                            (string=? var "mbox")
+                            (string=? var "expand-only")
+                            (string=? var "forward-only"))
+                        var]
+                       [else
+                        (begin
+                          (display (string-append "<opensmtpd-action-local-delivery-configuration> fieldname 'method' must be of type \n"
+                                                  "\"mbox\", \"expand-only\", \"forward-only\" \n"
+                                                  "<opensmtpd-lmtp-configuration>, <opensmtpd-maildir-configuration>, \n"
+                                                  "or <opensmtpd-mda-configuration>.\n"))
+                          (throw 'bad! var))]))))
+  (alias opensmtpd-action-local-delivery-configuration-alias
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-action-local-delivery-configuration" "alias"
+                                  (list false? opensmtpd-table-configuration?)))))
+  (ttl opensmtpd-action-local-delivery-configuration-ttl
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-local-delivery-configuration" "ttl"
+                                (list false? string?)))))
+  (user opensmtpd-action-local-delivery-configuration-user
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-local-delivery-configuration" "user"
+                                 (list false? string?)))))
+  (userbase opensmtpd-action-local-delivery-configuration-userbase
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-action-local-delivery-configuration" "userbase"
+                                     (list false? opensmtpd-table-configuration?)))))
+  (virtual opensmtpd-action-local-delivery-configuration-virtual
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-action-local-delivery-configuration" "virtual"
+                                    (list false? opensmtpd-table-configuration?)))))
+  (wrapper opensmtpd-action-local-delivery-configuration-wrapper
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-action-local-delivery-configuration" "wrapper"
+                                    (list false? string?))))))
+
+;; FIXME/TODO this is a valid opensmtpd-relay record
+;; (opensmtpd-action-relay-configuration
+;;  (pki (opensmtpd-pki-configuration
+;;        (domain "gnucode.me")
+;;        (cert "opensmtpd.scm")
+;;        (key "opensmtpd.scm"))))
+;; BUT how does it relay the email?  What host does it use?
+;; I think opensmtpd-relay-configuration needs "method" field.
+;; the method field might need to be another record...BUT basically the relay has to have a 'backup', 'backup-mx',
+;; or 'domain', or 'host' defined.
+(define-record-type* <opensmtpd-action-relay-configuration>
+  opensmtpd-action-relay-configuration make-opensmtpd-action-relay-configuration
+  opensmtpd-action-relay-configuration?
+  (name opensmtpd-action-relay-configuration-name
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "name"
+                                 (list string?))))
+        (default #f))
+  (backup opensmtpd-action-relay-configuration-backup ;; boolean
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-action-relay-configuration" "backup"
+                                   (list boolean?)))))
+  (backup-mx opensmtpd-action-relay-configuration-backup-mx ;; string mx name
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-action-relay-configuration" "backup-mx"
+                                      (list false? string?)))))
+  (helo opensmtpd-action-relay-configuration-helo
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "helo"
+                                 (list false? string? opensmtpd-table-configuration?))))
+        (default #f))
+  (helo-src opensmtpd-action-relay-configuration-helo-src
+        (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-action-relay-configuration" "helo-src"
+                                   (list false? string? opensmtpd-table-configuration?))))
+        (default #f))
+  (domain opensmtpd-action-relay-configuration-domain
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-action-relay-configuration" "domain"
+                                   (list false? opensmtpd-table-configuration?))))
+          (default #f))
+  (host opensmtpd-action-relay-configuration-host
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "host"
+                                 (list false? string?))))
+        (default #f))
+  (pki opensmtpd-action-relay-configuration-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-relay-configuration" "pki"
+                                (list false? opensmtpd-pki-configuration?)))))
+  (srs opensmtpd-action-relay-configuration-srs
+       (default #f)
+       (lambda (var)
+         (my/sanitize var "opensmtpd-action-relay-configuration" "srs"
+                      (list boolean?))))
+  (tls opensmtpd-action-relay-configuration-tls
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-relay-configuration" "tls"
+                                (list false? string?)))))
+  (auth opensmtpd-action-relay-configuration-auth
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "auth"
+                                 (list false? opensmtpd-table-configuration?))))
+        (default #f))
+  (mail-from opensmtpd-action-relay-configuration-mail-from
+             (default #f))
+  ;; string "127.0.0.1" or "<interface>" or "<table of IP addresses>"
+  ;; TODO should I do some sanitizing to make sure that the string? here is actually an IP address or a valid interface?
+  (src opensmtpd-action-relay-configuration-src
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-relay-configuration" "src"
+                                (list false? string? opensmtpd-table-configuration?))))
+       (default #f)))
+
+;; this record is used by <opensmtpd-filter-phase-configuration> &
+;; <opensmtpd-match-configuration>
+(define-record-type* <opensmtpd-option-configuration>
+  opensmtpd-option-configuration make-opensmtpd-option-configuration
+  opensmtpd-option-configuration?
+  (option opensmtpd-option-configuration-option
+          (default #f)
+          (sanitize (lambda (var)
+                      (if (and (string? var)
+                               (or (string-in-list? var (list "fcrdns" "rdns"
+                                                          "src" "helo"
+                                                          "auth" "mail-from"
+                                                          "rcpt-to"
+                                                          "for"
+                                                          "for any" "for local"
+                                                          "for domain" "for rcpt-to"
+                                                          "from any" "from auth"
+                                                          "from local" "from mail-from"
+                                                          "from rdns" "from socket"
+                                                          "from src" "auth"
+                                                          "helo" "mail-from"
+                                                          "rcpt-to" "tag" "tls"
+                                                          ))))
+                          var
+                          (begin
+                            (display (string-append "<opensmtpd-option-configuration> fieldname: 'option' is of type \n"
+                                                    "string.  The string can be either 'fcrdns', \n"
+                                                    " 'rdns', 'src', 'helo', 'auth', 'mail-from', or 'rcpt-to', \n"
+                                                    "'for', 'for any', 'for local', 'for domain', 'for rcpt-to', \n"
+                                                    "'from any', 'from auth', 'from local', 'from mail-from', 'from rdns', 'from socket', \n"
+                                                    "'from src', 'auth helo', 'mail-from', 'rcpt-to', 'tag', or 'tls' \n"
+                                                    ))
+                            (throw 'bad! var))))))
+  (not opensmtpd-option-configuration-not
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-option-configuration" "not"
+                                (list boolean?)))))
+  (regex opensmtpd-option-configuration-regex
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option-configuration" "regex"
+                                  (list boolean?)))))
+  (data opensmtpd-option-configuration-data
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option-configuration" "data"
+                                  (list false? string? opensmtpd-table-configuration?))))))
+
+(define-record-type* <opensmtpd-filter-phase-configuration>
+  opensmtpd-filter-phase-configuration make-opensmtpd-filter-phase-configuration
+  opensmtpd-filter-phase-configuration?
+  (name opensmtpd-filter-phase-configuration-name ;; string chain-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter-phase-configuration" "name"
+                                 (list string?)))))
+  (phase opensmtpd-filter-phase-configuration-phase ;; string
+              (default #f)
+              (sanitize (lambda (var)
+                          ;;(my/sanitize var "opensmtpd-filter-phase-configuration" "phase"
+                          ;;             (list (sanitize-configuration
+                          ;;                    (proc (lambda (value)
+                          ;;                            (and (string? var)
+                          ;;                                 (string-in-list? var (list "connect"
+                          ;;                                                            "helo"
+                          ;;                                                            "mail-from"
+                          ;;                                                            "rcpt-to"
+                          ;;                                                            "data"
+                          ;;                                                            "commit")))))
+                          ;;                    (error-message (list
+                          ;;                                    "<opensmtpd-filter-phase-configuration> fieldname: 'phase' is of type \n"
+                          ;;                                    "string.  The string can be either 'connect',"
+                          ;;                                    " 'helo', 'mail-from', 'rcpt-to', 'data', or 'commit.'\n ")))))
+                          (if (and (string? var)
+                                   (string-in-list? var (list "connect"
+                                                          "helo"
+                                                          "mail-from"
+                                                          "rcpt-to"
+                                                          "data"
+                                                          "commit")))
+                              var
+                              (begin
+                                (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'phase' is of type \n"
+                                                        "string.  The string can be either 'connect',"
+                                                        " 'helo', 'mail-from', 'rcpt-to', 'data', or 'commit.'\n "
+                                                        ))
+                                (throw 'bad! var)))
+                          )))
+
+  (options opensmtpd-filter-phase-configuration-options
+              (default #f)
+              (sanitize (lambda (var)
+                          ;; returns #t if list is a unique list of <opensmtpd-option-configuration>
+                          (define (list-of-opensmtpd-option-configuration? list)
+                            (and (list-of-type? list opensmtpd-option-configuration?)
+                                 (not (contains-duplicate? list))))
+
+                          (define (list-has-duplicates-or-non-opensmtpd-option-configuration list)
+                            (not (list-of-opensmtpd-option-configuration? list)))
+
+                          ;; input <opensmtpd-option-configuration>
+                          ;; return #t if <opensmtpd-option-configuration> fieldname 'option'
+                          ;; that needs a corresponding table has one.  Otherwise #f
+                          (define (opensmtpd-option-configuration-has-table? record)
+                            (define decision (opensmtpd-option-configuration-option record))
+                            (and (string? decision)
+                                 ;; if option needs a table, check for a table
+                                 (if (string-in-list? decision (list "src"
+                                                                     "helo"
+                                                                     "mail-from"
+                                                                     "rcpt-to"))
+                                     (opensmtpd-table-configuration? (opensmtpd-option-configuration-data record))
+                                     #t)))
+
+                          (define (list-of-opensmtpd-option-configuration-has-table? list)
+                            (list-of-type? list opensmtpd-option-configuration-has-table?))
+
+                          (define (some-opensmtpd-option-configuration-in-list-lack-table? list)
+                            (not (list-of-opensmtpd-option-configuration-has-table? list)))
+
+                          ;;each element in list is of type <opensmtpd-option-configuration>
+                          (cond [(list-has-duplicates-or-non-opensmtpd-option-configuration var)
+                                 (begin
+                                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'options' is a list of unique \n"
+                                                           "<opensmtpd-option-configuration> records.\n"))
+                                   (throw 'bad! var))]
+                                ;; if fieldname 'option' is of string 'src', 'helo', 'mail-from', 'rcpt-to', then there should be a table
+                                [(some-opensmtpd-option-configuration-in-list-lack-table? var)
+                                 (begin
+                                   (display (string-append "<opensmtpd-option-configuration>'s fieldname 'option' values of \n"
+                                                           "'src', 'helo', 'mail-from', or 'rcpt-to' need a corresponding 'table' \n"
+                                                           " of type <opensmtpd-table-configuration>. eg: \n"
+                                                           "(opensmtpd-option-configuration \n"
+                                                           "   (option \"src\")\n"
+                                                           "   (table (opensmtpd-table-configuration \n"
+                                                           "              (name \"src-table\")\n"
+                                                           "              (data (list \"hello\" \"cat\")))))\n"))
+                                   ;; TODO it would be nice if the var this error message throws in the bad
+                                   ;; <opensmtpd-option-configuration>, instead of the list of records.
+                                   (throw 'bad! var))]
+                                [else var]))))
+  (decision opensmtpd-filter-phase-configuration-decision
+            (default #f)
+            (sanitize (lambda (var)
+                        (if (and (string? var)
+                                 (string-in-list? var (list "bypass" "disconnect"
+                                                            "reject" "rewrite" "junk")))
+                            var
+                            (begin
+                              (display (string-append "<opensmtpd-filter-decision> fieldname: 'decision' is of type \n"
+                                                      "string.  The string can be either 'bypass',"
+                                                      " 'disconnect', 'reject', 'rewrite', or 'junk'.\n"))
+                              (throw 'bad! var))))))
+  (message opensmtpd-filter-phase-configuration-message
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-filter-phase-configuration" "message"
+                                    (list false? string?)))))
+  (value opensmtpd-filter-phase-configuration-value
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-filter-phase-configuration" "value"
+                                    (list false? number?))))))
+
+(define-record-type* <opensmtpd-filter-configuration>
+  opensmtpd-filter-configuration make-opensmtpd-filter-configuration
+  opensmtpd-filter-configuration?
+  (name opensmtpd-filter-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "name"
+                                 (list string?)))))
+  (exec opensmtpd-filter-exec
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "exec"
+                                 (list boolean?)))))
+  (proc opensmtpd-filter-configuration-proc ; a string like "rspamd" or the command to start it like "/path/to/rspamd --option=arg --2nd-option=arg2"
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-filter" "proc"
+                                      (list string?))))))
+
+;; There is another type of filter that opensmtpd supports, which is a filter chain.
+;; A filter chain is a list of <opensmtpd-filter-phase-configuration> and <opensmtpd-filter-configuration>.
+;; This lets you apply several filters under one filter name.  I could have defined
+;; a record type for it, but the record would only have had two fields: name and list-of-filters.
+;; Why write that as a record?  That's too simple.
+;; returns #t if list is a unique list of <opensmtpd-filter-configuration> or <opensmtpd-filter-phase-configuration>
+;; returns # otherwise
+(define (opensmtpd-filter-chain? %filters)
+  (and (list-of-unique-filter-or-filter-phase? %filters)
+       (< 1 (length %filters))))
+
+(define-record-type* <opensmtpd-listen-on-configuration>
+  opensmtpd-listen-on-configuration make-opensmtpd-listen-on-configuration
+  opensmtpd-listen-on-configuration?
+  ;; interface may be an IP address, interface group, or domain name
+  (interface opensmtpd-listen-on-configuration-interface
+             (default "lo"))
+  (family opensmtpd-listen-on-configuration-family
+          (default #f)
+          (sanitize (lambda (var)
+                      (cond
+                       [(eq? #f var) ;; var == #f
+                        var]
+                       [(and (string? var)
+                             (string-in-list? var (list "inet4" "inet6")))
+                        var]
+                       [else
+                        (begin
+                          (display "<opensmtpd-listen-on-configuration> fieldname 'family' must be string \"inet4\" or \"inet6\".\n")
+                          (throw 'bad! var))]))))
+  (auth opensmtpd-listen-on-configuration-auth
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-listen-on-configuration" "auth"
+                                 (list boolean? table-whose-data-are-assoc-list?)))))
+  (auth-optional opensmtpd-listen-on-configuration-auth-optional
+                 (default #f)
+                 (sanitize (lambda (var)
+                             (my/sanitize var "opensmtpd-listen-on-configuration" "auth-optional"
+                                          (list boolean?
+                                                table-whose-data-are-assoc-list?)))))
+  ;; TODO add a ca entry?
+  ;; string FIXME/TODO sanitize this to support a gexp.  That way way the
+  ;; includes directive can include my hacky scheme code that I use for opensmtpd-dkimsign.
+  (filters opensmtpd-listen-on-configuration-filters
+           (default #f)
+           (sanitize (lambda (var)
+                       (sanitize-filters var))))
+  (hostname opensmtpd-listen-on-configuration-hostname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-listen-on-configuration" "hostname"
+                                     (list false? string?)))))
+  (hostnames opensmtpd-listen-on-configuration-hostnames
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-listen-on-configuration" "hostnames"
+                                      (list false? table-whose-data-are-assoc-list?)))))
+  (mask-src opensmtpd-listen-on-configuration-mask-src
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-listen-on-configuration" "mask-src"
+                                     (list boolean?)))))
+  (disable-dsn opensmtpd-listen-on-configuration-disable-dsn
+          (default #f))
+  (pki opensmtpd-listen-on-configuration-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-listen-on-configuration" "pki"
+                                (list false? opensmtpd-pki-configuration?)))))
+  (port opensmtpd-listen-on-configuration-port
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-listen-on-configuration" "port"
+                                 (list false? integer?)))))
+  (proxy-v2 opensmtpd-listen-on-configuration-proxy-k2
+            (default #f))
+  (received-auth opensmtpd-listen-on-configuration-received-auth
+                 (default #f))
+  ;; TODO add in a senders option!
+  ;; string or <opensmtpd-senders> record
+  ;; (senders opensmtpd-listen-on-configuration-senders
+  ;;          (sanitize (lambda (var)
+  ;;                      (my/sanitize var "opensmtpd-listen-on-configuration" "port" (list false? integer?))))
+  ;;          (default #f))
+  (secure-connection opensmtpd-listen-on-configuration-secure-connection
+                     (default #f)
+                     (sanitize (lambda (var)
+                                 (cond [(boolean? var)
+                                        var]
+                                       [(and (string? var)
+                                             (string-in-list? var
+                                                              (list "smtps" "tls"
+                                                                    "tls-require"
+                                                                    "tls-require-verify")))
+                                        var]
+                                       [else
+                                        (begin
+                                          (display (string-append "<opensmtd-listen-on> fieldname 'secure-connection' can be \n"
+                                                                  "one of the following strings: \n'smtps', 'tls', 'tls-require', \n"
+                                                                  "or 'tls-require-verify'.\n"))
+                                          (throw 'bad! var))]))))
+  (tag opensmtpd-listen-on-configuration-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-listen-on-configuration" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+(define-record-type* <opensmtpd-listen-on-socket-configuration-configuration>
+  opensmtpd-listen-on-socket-configuration-configuration make-opensmtpd-listen-on-socket-configuration-configuration
+  opensmtpd-listen-on-socket-configuration-configuration?
+  ;; false or <opensmtpd-filter-configuration> or list of <opensmtpd-filter-configuration>
+  (filters opensmtpd-listen-on-socket-configuration-configuration-filters
+           (sanitize (lambda (var)
+                       (sanitize-filters var)))
+          (default #f))
+  (mask-src opensmtpd-listen-on-socket-configuration-configuration-mask-src
+            (default #f))
+  (tag opensmtpd-listen-on-socket-configuration-configuration-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-listen-on-configuration" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+
+(define-record-type* <opensmtpd-match-configuration>
+  opensmtpd-match-configuration make-opensmtpd-match-configuration
+  opensmtpd-match-configuration?
+  ;;TODO? Perhaps I should add in a reject fieldname.  If reject
+  ;;is #t, then the match record will be a reject match record.
+  ;; (opensmtpd-match (reject #t)) vs. (opensmtpd-match (action 'reject))
+  ;; To do this, I will also have to  'reject' mutually exclusive. AND an match with 'reject' can have no action defined.
+  (action opensmtpd-match-configuration-action
+          (default #f)
+          (sanitize (lambda (var)
+                      (if (or (opensmtpd-action-relay-configuration? var)
+                              (opensmtpd-action-local-delivery-configuration? var)
+                              (eq? (quote reject) var))
+                          var
+                          (begin
+                            (display
+                             (string-append "<opensmtpd-match-configuration> fieldname 'action' is of type <opensmtpd-action-relay-configuration>, \n"
+                                            "<opensmtpd-action-local-delivery-configuration>, or (quote reject).\n"
+                                            "If its var is (quote reject), then the match rejects the incoming message\n"
+                                            "during the SMTP dialogue.\n"))
+                            (throw 'bad! var))))))
+  (options opensmtpd-match-configuration-options
+           (default #f)
+           (sanitize (lambda (var)
+                       (cond ((not var)
+                              #f)
+                             ((not (list-of-unique-opensmtpd-option-configuration? var))
+                              (throw-error var '("<opensmtpd-match-configuration> fieldname 'options' is a list of unique \n"
+                                                 "<opensmtpd-option-configuration> records. \n")))
+                           (else (sanitize-list-of-options-for-match-configuration var)))))))
+
+(define-record-type* <opensmtpd-smtp-configuration>
+  opensmtpd-smtp-configuration make-opensmtpd-smtp-configuration
+  opensmtpd-smtp-configuration?
+  (ciphers opensmtpd-smtp-configuration-ciphers
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-smtp-configuration" "ciphers"
+                                    (list false? string?)))))
+  (limit-max-mails opensmtpd-smtp-configuration-limit-max-mails
+                   (default #f)
+                   (sanitize (lambda (var)
+                               (my/sanitize var "opensmtpd-smtp-configuration" "limit-max-mails"
+                                            (list false? integer?)))))
+  (limit-max-rcpt opensmtpd-smtp-configuration-limit-max-rcpt
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp-configuration" "limit-max-rcpt"
+                                           (list false? integer?)))))
+  (max-message-size opensmtpd-smtp-configuration-max-message-size
+                    (default #f)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-smtp-configuration" "max-message-size"
+                                             (list false? integer? string?)))))
+  ;; FIXME/TODO the sanitize function of sub-addr-delim should accept a string of length one not string?
+  (sub-addr-delim opensmtpd-smtp-configuration-sub-addr-delim
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp-configuration" "sub-addr-delim"
+                                           (list false? integer? string?))))))
+
+(define-record-type* <opensmtpd-srs-configuration>
+  opensmtpd-srs-configuration make-opensmtpd-srs-configuration
+  opensmtpd-srs-configuration?
+  ;; TODO should this be a file?
+  (key opensmtpd-srs-configuration-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-srs-configuration" "key"
+                                (list false? boolean? string?)))))
+  ;; TODO should this also be a file?
+  (backup-key opensmtpd-srs-configuration-backup-key
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-srs-configuration" "backup-key"
+                                       (list false? integer?)))))
+  (ttl-delay opensmtpd-srs-configuration-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-srs-configuration" "ttl-delay"
+                                      (list false? string?))))))
+
+(define-record-type* <opensmtpd-queue-configuration>
+  opensmtpd-queue-configuration make-opensmtpd-queue-configuration
+  opensmtpd-queue-configuration?
+  (compression opensmtpd-queue-configuration-compression
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-queue-configuration" "compression"
+                                        (list boolean?)))))
+  (encryption opensmtpd-queue-configuration-encryption
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-queue-configuration" "encryption"
+                                       (list boolean? file-exists? string?)))))
+  (ttl-delay opensmtpd-queue-configuration-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-queue-configuration" "ttl-delay"
+                                      (list false? string?))))))
+
 (define-record-type* <opensmtpd-configuration>
   opensmtpd-configuration make-opensmtpd-configuration
   opensmtpd-configuration?
-  (package     opensmtpd-configuration-package
-               (default opensmtpd))
+  (package opensmtpd-configuration-package
+           (default opensmtpd))
   (config-file opensmtpd-configuration-config-file
-               (default %default-opensmtpd-config-file)))
+               (default #f))
+  ;; FIXME/TODO should I include a admd authservid entry?
+
+  ;; TODO sanitize this properly with perhaps a <sanitize-configuration>.
+  (bounce opensmtpd-configuration-bounce
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-configuration" "bounce"
+                                   (list false? list?)))))
+  (cas opensmtpd-configuration-cas
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "cas"
+                                (list false? list-of-opensmtpd-ca-configuration?)))))
+  ;; list of many records of type opensmtpd-listen-on-configuration
+  (listen-ons opensmtpd-configuration-listen-ons
+              (default (list (opensmtpd-listen-on-configuration)))
+              (sanitize (lambda (var)
+                          (if (list-of-opensmtpd-listen-on-configuration? var)
+                              var
+                              (begin
+                                (display "<opensmtpd-configuration> fieldname 'listen-ons' expects a list of records ")
+                                (display "of one or more unique <opensmtpd-listen-on-configuration> records.\n")
+                                (throw 'bad! var))))))
+  ;; accepts type <opensmtpd-listen-on-socket-configuration-configuration>
+  (listen-on-socket opensmtpd-configuration-listen-on-socket
+                    (default (opensmtpd-listen-on-socket-configuration-configuration)))
+  (includes opensmtpd-configuration-includes ;; list of strings of absolute path names
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-configuration" "includes"
+                                     (list false? list-of-strings?)))))
+  (matches opensmtpd-configuration-matches
+           (default (list (opensmtpd-match-configuration
+                           (action (opensmtpd-action-local-delivery-configuration
+                                    (name "local")
+                                    (method "mbox")))
+                           (options (list
+                                     (opensmtpd-option-configuration
+                                      (option "for local")))))
+                          (opensmtpd-match-configuration
+                           (action (opensmtpd-action-relay-configuration
+                                    (name "outbound")))
+                           (options (list
+                                     (opensmtpd-option-configuration
+                                      (option "from local"))
+                                     (opensmtpd-option-configuration
+                                      (option "for any")))))))
+           ;; TODO perhaps I should sanitize this function like I sanitized the 'filters'.
+           ;; I definitely should sanitize this function a bit more.  For example, you could have two different
+           ;; actions, one for local delivery and one for remote, with the same name.  I should make sure that
+           ;; I have no two different actions with the same name.
+           (sanitize (lambda (var)
+                       ;; Should we do more sanitizing here?  eg: "from socket" should NOT have a table or value
+                       var
+                       (my/sanitize var "opensmtpd-configuration" "matches"
+                                    (list list-of-unique-opensmtpd-match-configuration?)))))
+  ;; list of many records of type mda-wrapper
+  ;; TODO/FIXME support using gexps here
+  ;; eg (list "name" gexp)
+  (mda-wrappers opensmtpd-configuration-mda-wrappers
+                (default #f)
+                (sanitize (lambda (var)
+                            (my/sanitize var
+                                         "opensmtpd-configuration"
+                                         "mda-wrappers"
+                                         (list false? string?)))))
+  (mta-max-deferred opensmtpd-configuration-mta-max-deferred
+                    (default 100)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-configuration" "mta-max-deferred"
+                                             (list number?)))))
+
+  ;; TODO should I add a fieldname proc _proc-name_ _command_ as found in the man 5 smtpd.conf ?
+
+  (queue opensmtpd-configuration-queue
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-configuration" "queue"
+                                  (list false? opensmtpd-queue-configuration?)))))
+  (smtp opensmtpd-configuration-smtp
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-configuration" "smtp"
+                                 (list false? opensmtpd-smtp-configuration?)))))
+  (srs opensmtpd-configuration-srs
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "srs"
+                                (list false? opensmtpd-srs-configuration?))))))
+
+;; This is a non-exported record for passing around sanitize procedures.
+;; As of 5/2/2022 I am not using it.  I should probably just delete it.
+(define-record-type* <sanitize-configuration>
+  sanitize-configuration make-sanitize-configuration
+  sanitize-configuration?
+  (proc sanitize-configuration-proc
+          (default #f)
+          ;;(sanitize (lambda (var) (procedure? var)))
+          )
+  (args sanitize-configuration-args
+       (default #f)
+       ;;(sanitize (lambda (var) (lambda (var) (list? var))))
+       )
+  (error-message sanitize-configuration-error-message
+         (default #f)
+         ;;(sanitize (lambda (var) (list? var)))
+         )
+  (error-if-proc-fails sanitize-configuration-error-if-proc-fails
+                       (default #f)))
+
+;; this help procedure is used 3 or 4 times by sanitize-list-of-options-for-match-configuration
+(define (throw-error-duplicate-option option error-arg)
+  (throw-error error-arg
+               (list "<opensmtpd-match-configuration>'s fieldname 'options' has two\n"
+                     (string-append "<opensmtpd-option-configuration> records with fieldname 'option' with value '" option "'. \n")
+                     (string-append "You can only have one option with value '" option "' in the options list.\n"))))
+
+;; this procedure sanitizes the fieldname opensmtpd-match-configuration-options
+(define* (sanitize-list-of-options-for-match-configuration %options)
+  (let loop ([%traversing-options %options]
+             [%sanitized-options '()])
+    (if (null? %traversing-options)
+           (remove false?
+                   (list
+                    (assoc-ref %sanitized-options "for")
+                    (assoc-ref %sanitized-options "from")
+                    (assoc-ref %sanitized-options "auth")
+                    (assoc-ref %sanitized-options "helo")
+                    (assoc-ref %sanitized-options "mail-from")
+                    (assoc-ref %sanitized-options "rcpt-to")
+                    (assoc-ref %sanitized-options "tag")
+                    (assoc-ref %sanitized-options "tls")))
+          (let* ((option-record (car %traversing-options))
+                 (option-string (opensmtpd-option-configuration-option option-record)))
+            (cond [(string=? "auth" option-string)
+                   (if (assoc-ref %sanitized-options "auth")
+                       (throw-error-duplicate-option "auth" %traversing-options)
+                       (loop (cdr %traversing-options) (alist-cons "auth" option-record %sanitized-options)))]
+                  [(string=? "helo" option-string)
+                   (cond [(assoc-ref %sanitized-options "helo")
+                          (throw-error-duplicate-option "helo" %traversing-options)]
+                         [(not (opensmtpd-option-configuration-data option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'helo' \n"
+                                             "must have a 'data' of type string or <opensmtpd-table-configuration>.\n"))]
+                         [else (loop (cdr %traversing-options) (alist-cons "helo" option-record %sanitized-options))])]
+                  [(string=? "mail-from" option-string)
+                   (cond ((assoc-ref %sanitized-options "mail-from")
+                          (throw-error-duplicate-option "mail-from" %traversing-options))
+                         ((not (opensmtpd-option-configuration-data option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'mail-from' \n"
+                                             "must have a 'data' of type string or <opensmtpd-table-configuration>.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "mail-from" option-record %sanitized-options))))]
+                  [(string=? "rcpt-to" option-string)
+                   (cond [(assoc-ref %sanitized-options "rcpt-to")
+                          (throw-error-duplicate-option "rcpt-to" %traversing-options)]
+                         [(not (opensmtpd-option-configuration-data option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'rcpt-to' \n"
+                                             "must have a 'data' of type string or <opensmtpd-table-configuration>.\n"))]
+                         [else (loop (cdr %traversing-options) (alist-cons "rcpt-to" option-record %sanitized-options))])]
+                  [(string=? "tag" option-string)
+                   (cond ((assoc-ref %sanitized-options "tag")
+                          (throw-error-duplicate-option "tag" %traversing-options))
+                         ((not (string? (opensmtpd-option-configuration-data option-record)))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'tag' \n"
+                                             "must have a 'data' of type string.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "tag" option-record %sanitized-options))))]
+                  [(string=? "tls" option-string)
+                   (cond [(assoc-ref %sanitized-options "tls")
+                          (throw-error-duplicate-option "tls" %traversing-options)]
+                         [(or (opensmtpd-option-configuration-data option-record)
+                              (opensmtpd-option-configuration-regex option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'tls' \n"
+                                             "cannot have a string or table 'data'.\n"))]
+                         [else (loop (cdr %traversing-options) (alist-cons "tls" option-record %sanitized-options))])]
+                  [(string=? "for" (substring option-string 0 3))
+                   (cond ((assoc-ref %sanitized-options "for")
+                          (throw-error %options
+                                       `("<opensmtpd-match-configuration>'s fieldname 'options' can only have one 'for' option. \n"
+                                         "But '" ,option-string "' and '"
+                                         ,(opensmtpd-option-configuration-option (assoc-ref %sanitized-options "for")) "' are present.\n")))
+                         ((and (string-in-list? option-string (list "for any" "for local")) ; for any cannot have a data field.
+                               (or (opensmtpd-option-configuration-data option-record)
+                                   (opensmtpd-option-configuration-regex option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'for any' \n"
+                                             "or 'for local', then its 'data' and 'regex' field must be #f. \n")))
+                         ((and (string-in-list? option-string (list "for domain" "for rcpt-to")) ; for domain must have a data field.
+                               (not (opensmtpd-option-configuration-data option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'for domain' \n"
+                                             "or 'for rcpt-to', then its 'data' field must be a string or an \n"
+                                             "<opensmtpd-table-configuration> record.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "for" option-record %sanitized-options))))]
+                  [(string=? "from" (substring option-string 0 4))
+                   (cond ((assoc-ref %sanitized-options "from")
+                          (throw-error %options
+                                       `("<opensmtpd-match-configuration>'s fieldname 'options' can only have one 'from' option. \n"
+                                         "But '" ,option-string "' and '"
+                                         ,(opensmtpd-option-configuration-option (assoc-ref %sanitized-options "from")) "' are present.\n")))
+                         ((and (string-in-list? option-string (list "from any" "from local" "from socket")) ; for any cannot have a data field.
+                               (or (opensmtpd-option-configuration-data option-record)
+                                   (opensmtpd-option-configuration-regex option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'from any', \n"
+                                             " 'from local', or 'from socket', then its 'data' and 'regex' field must be #f. \n")))
+                         ((and (string-in-list? option-string (list "from mail-from" "from src")) ; for domain must have a data field.
+                               (not (opensmtpd-option-configuration-data option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'from mail-from' \n"
+                                             "or 'from src', then its 'data' field must be a string or an \n"
+                                             "<opensmtpd-table-configuration> record.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "from" option-record %sanitized-options))))])))))
+
+;; some procedures for <opensmtpd-listen-on-configuration> and
+;; <opensmtpd-listen-on-socket-configuration-configuration>.
+(define (sanitize-filters %list)
+  ;; the order of the first two tests in this cond is important.
+  ;; (false?) has to be 1st and (list-has-duplicates-or-non-filters?) has to be second.
+  ;; You may optionally re-order the other alternates in the cond.
+  (cond [(false? %list)
+         #f]
+        [(list-has-duplicates-or-non-filters? %list)
+         (begin
+           (display (string-append "<opensmtpd-listen-on-configuration> fieldname: 'filters' is a list, in which each unique element \n"
+                                   "is of type <opensmtpd-filter-configuration> or <opensmtpd-filter-phase-configuration>.\n"))
+           (throw 'bad! %list))]
+        [else
+         (let loop ([%traversing-list %list]
+                    [%original-list %list])
+           (if (null? %traversing-list)
+               %original-list
+               (cond
+                [(opensmtpd-filter-configuration? (car %traversing-list))
+                 (loop (cdr %traversing-list) %original-list)]
+                [(filter-phase-has-message-and-value? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> cannot have defined fieldnames 'value' \n"
+                                           "and 'message'.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-decision-lacks-proper-message? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'decision' options \n"
+                                           "\"disconnect\" and \"reject\" require fieldname 'message' to have a string.\n"
+                                           "The 'message' string must be RFC commpliant, which means that the string \n"
+                                           "must begin with a 4xx or 5xx status code.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-lacks-proper-value? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'decision' option \n"
+                                           "\"rewrite\" requires fieldname 'value' to have a number.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-has-incorrect-junk-or-bypass? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname 'decision' option \n"
+                                           "\"junk\" or 'bypass' cannot have a defined fieldnames 'message' or 'value'.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-junks-after-commit? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname 'decision' option \n"
+                                           "\"junk\" cannot junk an email during 'phase' \"commit\".\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [else (loop (cdr %traversing-list) %original-list)])))]))
+
+(define (list-has-duplicates-or-non-filters? list)
+  (not (list-of-unique-filter-or-filter-phase? list)))
+
+(define (filter-phase-has-message-and-value? record)
+  (and (opensmtpd-filter-phase-configuration-message record)
+       (opensmtpd-filter-phase-configuration-value record)))
+
+;; return #t if phase needs a message. Or if the message did not start with a 4xx or 5xx status code.
+;; otherwise #f
+(define (filter-phase-decision-lacks-proper-message? record)
+  (define decision (opensmtpd-filter-phase-configuration-decision record))
+  (if (string-in-list? decision (list "disconnect" "reject"))
+      ;; this message needs to be RFC compliant, meaning
+      ;; that it need to start with 4xx or 5xx status code
+      (cond [(eq? #f (opensmtpd-filter-phase-configuration-message record))
+             #t]
+            [(string? (opensmtpd-filter-phase-configuration-message record))
+             (let ((number (string->number
+                            (substring
+                             (opensmtpd-filter-phase-configuration-message record) 0 3))))
+               (if (and (number? number)
+                        (and (< number 600) (> number 399)))
+                   #f
+                   #t))])
+      #f))
+
+;; 'decision' "rewrite" requires 'value' to be a number.
+(define (filter-phase-lacks-proper-value? record)
+  (define decision (opensmtpd-filter-phase-configuration-decision record))
+  (if (string=? "rewrite" decision)
+      (if (and (number? (opensmtpd-filter-phase-configuration-value record))
+               (eq? #f (opensmtpd-filter-phase-configuration-message record)))
+          #f
+          #t)
+      #f))
+
+;; 'decision' "junk" or "bypass" cannot have a message or a value.
+(define (filter-phase-has-incorrect-junk-or-bypass? record)
+  (and
+   (string-in-list?
+    (opensmtpd-filter-phase-configuration-decision record)
+    (list "junk" "bypass"))
+   (or
+    (opensmtpd-filter-phase-configuration-value record)
+    (opensmtpd-filter-phase-configuration-message record))))
+
+(define (filter-phase-junks-after-commit? record)
+  (and (string=? (opensmtpd-filter-phase-configuration-decision record) "junk")
+       (string=? (opensmtpd-filter-phase-configuration-phase record) "commit")))
+
+;; returns #t if list is a unique list of <opensmtpd-filter-configuration> or <opensmtpd-filter-phase-configuration>
+;; returns # otherwise
+(define (list-of-unique-filter-or-filter-phase? %filters)
+  (and (list? %filters)
+       (not (null? %filters))
+       ;; this list is made up of only <opensmtpd-filter-phase-configuration> or <opensmtpd-filter-configuration>
+       (primitive-eval
+        (cons 'and (map (lambda (filter)
+                          (or (opensmtpd-filter-configuration? filter)
+                              (opensmtpd-filter-phase-configuration? filter)))
+                        %filters)))
+       (not (contains-duplicate? %filters))))
+
+(define (throw-error var %strings)
+  (display (apply string-append %strings))
+  (throw 'bad! var))
+
+;; this is used for sanitizing <opensmtpd-filter-phase-configuration> fieldname 'options'
+(define (contains-duplicate? list)
+  (if (null? list)
+      #f
+      (or
+      ;; check if (car list) is in (cdr list)
+       (primitive-eval (cons 'or
+                                (map (lambda (var) (equal? var (car list)))
+                                     (cdr list))))
+       ;; check if (cdr list) contains duplicate
+       (contains-duplicate? (cdr list)))))
+
+;; given a list and procedure, this tests that each element of list is of type
+;; ie: (list-of-type? list string?) tests each list is of type string.
+(define (list-of-type? list proc?)
+  (if (and (list? list)
+           (not (null? list)))
+      (let loop ([list list])
+        (if (null? list)
+            #t
+            (if (proc? (car list))
+                (loop (cdr list))
+                #f)))
+      #f))
+
+(define (list-of-strings? list)
+  (list-of-type? list string?))
+
+(define (list-of-unique-opensmtpd-option-configuration? list)
+  (and (list-of-type?
+        list opensmtpd-option-configuration?)
+       (not (contains-duplicate? list))))
+
+(define (list-of-opensmtpd-ca-configuration? list)
+  (list-of-type? list opensmtpd-ca-configuration?))
+
+(define (list-of-opensmtpd-pki-configuration? list)
+  (list-of-type? list opensmtpd-pki-configuration?))
+
+(define (list-of-opensmtpd-listen-on-configuration? list)
+  (and (list-of-type? list opensmtpd-listen-on-configuration?)
+       (not (contains-duplicate? list))))
+
+(define (list-of-unique-opensmtpd-match-configuration? list)
+  (and (list-of-type? list opensmtpd-match-configuration?)
+       (not (contains-duplicate? list))))
+
+(define* (list-of-strings->string list
+                                  #:key
+                                  (string-delimiter ", ")
+                                  (postpend "")
+                                  (append "")
+                                  (drop-right-number 2))
+  (string-drop-right
+   (string-append (let loop ([list list])
+                    (if (null? list)
+                        ""
+                        (string-append append (car list) postpend
+                                       string-delimiter
+                                       (loop (cdr list)))))
+                  append)
+   drop-right-number))
+
+;; at the moment I cannot define this by using list-of-type?
+;; the first (not (null? assoc-list)) prevents that.
+(define (assoc-list? assoc-list)
+  (list-of-type? assoc-list (lambda (pair)
+                              (if (and (pair? pair)
+                                       (string? (car pair))
+                                       (string? (cdr pair)))
+                                  #t
+                                  #f))))
+
+(define* (variable->string var #:key (append "") (postpend " "))
+  (let ([var (if (number? var)
+                 (number->string var)
+                 var)])
+    (if var
+        (string-append append var postpend)
+        "")))
+
+;; this procedure takes in one argument.
+;; if that argument is an <opensmtpd-table-configuration> whose fieldname 'values' is an assoc-list, then it returns
+;; #t, #f if otherwise.
+;; TODO should I remove these two functions?  And instead use the (opensmtpd-table-configuration-type) procedure?
+(define (table-whose-data-are-assoc-list? table)
+  (if (not (opensmtpd-table-configuration? table))
+      #f
+      (assoc-list? (opensmtpd-table-configuration-data table))))
+
+;; this procedure takes in one argument
+;; if that argument is an <opensmtpd-table-configuration> whose fieldname 'values' is a list of strings, then it returns
+;; #t, #f if otherwise.
+(define (table-whose-data-are-a-list-of-strings? table)
+  (if (not (opensmtpd-table-configuration? table))
+      #f
+      (list-of-strings? (opensmtpd-table-configuration-data table))))
+
+;; these next few functions help me to turn <table>s
+;; into strings suitable to fit into "opensmtpd.conf".
+(define (assoc-list->string assoc-list)
+  (string-drop-right
+   (let loop ([assoc-list assoc-list])
+     (if (null? assoc-list)
+         ""
+         ;; pair is (cons "hello" "world") -> ("hello" . "world")
+         (let ([pair (car assoc-list)])
+           (string-append
+            "\"" (car pair)  "\""
+            " = "
+            "\"" (cdr pair) "\""
+            ", "
+            (loop (cdr assoc-list))))))
+   2))
+
+;; can be of type: (quote list-of-strings) or (quote assoc-list)
+(define (opensmtpd-table-configuration->string table)
+  (string-append "table " (opensmtpd-table-configuration-name table) " "
+                 (let ([type (opensmtpd-table-configuration-type table)])
+                   (cond [(eq? type (quote list-of-strings))
+                          (string-append "{ " (list-of-strings->string (opensmtpd-table-configuration-data table)
+                                                                       #:append "\""
+                                                                       #:drop-right-number 3
+                                                                       #:postpend "\"") " }")]
+                         [(eq? type (quote assoc-list))
+                          (string-append "{ " (assoc-list->string (opensmtpd-table-configuration-data table)) " }")]
+                         [(eq? type (quote db))
+                          (string-append "db:" (opensmtpd-table-configuration-data table))]
+                         [(eq? type (quote file))
+                          (string-append "file:" (opensmtpd-table-configuration-data table))]
+                         [else (throw 'youMessedUp table)]))
+                 " \n"))
+
+;;  The following functions convert various records into strings.
+
+(define (opensmtpd-listen-on-configuration->string record)
+  (string-append "listen on "
+                 (opensmtpd-listen-on-configuration-interface record) " "
+                 (let* ([hostname (opensmtpd-listen-on-configuration-hostname record)]
+                        [hostnames (if (opensmtpd-listen-on-configuration-hostnames record)
+                                       (opensmtpd-table-configuration-name (opensmtpd-listen-on-configuration-hostnames record))
+                                       #f)]
+                        [filters (opensmtpd-listen-on-configuration-filters record)]
+                        [filter-name (if filters
+                                         (if (< 1 (length filters))
+                                             (generate-filter-chain-name filters)
+                                             (if (opensmtpd-filter-configuration? (car filters))
+                                                 (opensmtpd-filter-configuration-name (car filters))
+                                                 (opensmtpd-filter-phase-configuration-name (car filters))))
+                                         #f)]
+                        [mask-src (opensmtpd-listen-on-configuration-mask-src record)]
+                        [tag (opensmtpd-listen-on-configuration-tag record)]
+                        [secure-connection (opensmtpd-listen-on-configuration-secure-connection record)]
+                        [port (opensmtpd-listen-on-configuration-port record)]
+                        [pki (opensmtpd-listen-on-configuration-pki record)]
+                        [auth (opensmtpd-listen-on-configuration-auth record)]
+                        [auth-optional (opensmtpd-listen-on-configuration-auth-optional record)])
+                   (string-append
+                    (if mask-src
+                        (string-append "mask-src ")
+                        "")
+                    (variable->string hostname #:append "hostname ")
+                    (variable->string hostnames #:append "hostnames <" #:postpend "> ")
+                    (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+                    (variable->string tag #:append "tag \"" #:postpend "\" ")
+                    (if secure-connection
+                        (cond [(string=? "smtps" secure-connection)
+                               "smtps "]
+                              [(string=? "tls" secure-connection)
+                               "tls "]
+                              [(string=? "tls-require" secure-connection)
+                               "tls-require "]
+                              [(string=? "tls-require-verify" secure-connection)
+                               "tls-require verify "])
+                        "")
+                    (variable->string port #:append "port " #:postpend " ")
+                    (if pki
+                        (variable->string (opensmtpd-pki-configuration-domain pki) #:append "pki ")
+                        "")
+                    (if auth
+                        (string-append "auth "
+                                       (if (opensmtpd-table-configuration? auth)
+                                           (string-append "<" (opensmtpd-table-configuration-name auth) "> ")
+                                           ""))
+                        "")
+                    (if auth-optional
+                        (string-append "auth-optional "
+                                       (if (opensmtpd-table-configuration? auth-optional)
+                                           (string-append "<" (opensmtpd-table-configuration-name auth-optional) "> ")
+                                           ""))
+                        "")
+                    "\n"))))
+
+(define (opensmtpd-listen-on-socket-configuration->string record)
+  (string-append "listen on socket "
+                 (let* ([filters (opensmtpd-listen-on-socket-configuration-configuration-filters record)]
+                        [filter-name (if filters
+                                         (if (< 1 (length filters))
+                                             (generate-filter-chain-name filters)
+                                             (if (opensmtpd-filter-configuration? (car filters))
+                                                 (opensmtpd-filter-configuration-name (car filters))
+                                                 (opensmtpd-filter-phase-configuration-name (car filters))))
+                                         #f)]
+                        [mask-src (opensmtpd-listen-on-socket-configuration-configuration-mask-src record)]
+                        [tag (opensmtpd-listen-on-socket-configuration-configuration-tag record)])
+                   (string-append
+                    (if mask-src
+                        (string-append "mask-src ")
+                        "")
+                    (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+                    (variable->string tag #:append "tag \"" #:postpend "\" ")
+                    "\n"))))
+
+(define (opensmtpd-action-relay-configuration->string record)
+  (let ([backup (opensmtpd-action-relay-configuration-backup record)]
+        [backup-mx (opensmtpd-action-relay-configuration-backup-mx record)]
+        [helo (opensmtpd-action-relay-configuration-helo record)]
+        ;; helo-src can either be a string IP address or an <opensmtpd-table-configuration>
+        [helo-src (if (opensmtpd-action-relay-configuration-helo-src record)
+                      (if (string? (opensmtpd-action-relay-configuration-helo-src record))
+                          (opensmtpd-action-relay-configuration-helo-src record)
+                          (string-append "<\""
+                                         (opensmtpd-table-configuration-name
+                                          (opensmtpd-action-relay-configuration-src record))
+                                         "\">"))
+                      #f)]
+        [domain (if (opensmtpd-action-relay-configuration-domain record)
+                    (opensmtpd-table-configuration-name
+                     (opensmtpd-action-relay-configuration-domain record))
+                    #f)]
+        [host (opensmtpd-action-relay-configuration-host record)]
+        [name (opensmtpd-action-relay-configuration-name record)]
+        [pki (if (opensmtpd-action-relay-configuration-pki record)
+                 (opensmtpd-pki-configuration-domain (opensmtpd-action-relay-configuration-pki record))
+                 #f)]
+        [srs (opensmtpd-action-relay-configuration-srs record)]
+        [tls (opensmtpd-action-relay-configuration-tls record)]
+        [auth (if (opensmtpd-action-relay-configuration-auth record)
+                  (opensmtpd-table-configuration-name
+                   (opensmtpd-action-relay-configuration-auth record))
+                  #f)]
+        [mail-from (opensmtpd-action-relay-configuration-mail-from record)]
+        ;; src can either be a string IP address or an <opensmtpd-table-configuration>
+        [src (if (opensmtpd-action-relay-configuration-src record)
+                 (if (string? (opensmtpd-action-relay-configuration-src record))
+                     (opensmtpd-action-relay-configuration-src record)
+                     (string-append "<\""
+                                    (opensmtpd-table-configuration-name
+                                     (opensmtpd-action-relay-configuration-src record))
+                                    "\">"))
+                 #f)]
+        )
+    (string-append
+     "\""
+     name
+     "\" " "relay "
+     ;;FIXME should I always quote the host fieldname? do I need to quote localhost via "localhost" ?
+     (variable->string host #:append "host \"" #:postpend "\" ")
+     (variable->string backup)
+     (variable->string backup-mx #:append "backup mx ")
+     (variable->string helo #:append "helo ")
+     (variable->string helo-src #:append "helo-src ")
+     (variable->string domain #:append "domain <\"" #:postpend "\"> ")
+     (variable->string host #:append "host ")
+     (variable->string pki #:append "pki ")
+     (variable->string srs)
+     (variable->string tls #:append "tls ")
+     (variable->string auth #:append "auth <" #:postpend "> ")
+     (variable->string mail-from #:append "mail-from ")
+     (variable->string src #:append "src ")
+     "\n")))
+
+(define (opensmtpd-lmtp-configuration->string record)
+  (string-append "lmtp "
+                 (opensmtpd-lmtp-configuration-destination record)
+                 (if (opensmtpd-lmtp-configuration-rcpt-to record)
+                     (begin
+                       " " (opensmtpd-lmtp-configuration-rcpt-to record))
+                     "")))
+
+(define (opensmtpd-mda-configuration->string record)
+  (string-append "mda "
+                 (opensmtpd-mda-configuration-command record) " "))
+
+(define (opensmtpd-maildir-configuration->string record)
+  (string-append "maildir "
+                 "\""
+                 (if (opensmtpd-maildir-configuration-pathname record)
+                     (opensmtpd-maildir-configuration-pathname record)
+                     "~/Maildir")
+                 "\""
+                 (if (opensmtpd-maildir-configuration-junk record)
+                     " junk "
+                     " ")))
+
+(define (opensmtpd-action-local-delivery-configuration->string record)
+  (let ([name (opensmtpd-action-local-delivery-configuration-name record)]
+        [method (opensmtpd-action-local-delivery-configuration-method record)]
+        [alias (if (opensmtpd-action-local-delivery-configuration-alias record)
+                   (opensmtpd-table-configuration-name
+                    (opensmtpd-action-local-delivery-configuration-alias record))
+                   #f)]
+        [ttl (opensmtpd-action-local-delivery-configuration-ttl record)]
+        [user (opensmtpd-action-local-delivery-configuration-user record)]
+        [userbase (if (opensmtpd-action-local-delivery-configuration-userbase record)
+                      (opensmtpd-table-configuration-name
+                       (opensmtpd-action-local-delivery-configuration-userbase record))
+                      #f)]
+        [virtual (if (opensmtpd-action-local-delivery-configuration-virtual record)
+                     (opensmtpd-table-configuration-name
+                      (opensmtpd-action-local-delivery-configuration-virtual record))
+                     #f)]
+        [wrapper (opensmtpd-action-local-delivery-configuration-wrapper record)])
+    (string-append
+     "\"" name "\" "
+     (cond [(string? method)
+            (string-append method " ")]
+           [(opensmtpd-mda-configuration? method)
+            (opensmtpd-mda-configuration->string method)]
+           [(opensmtpd-lmtp-configuration? method)
+            (opensmtpd-lmtp-configuration->string method)]
+           [(opensmtpd-maildir-configuration? method)
+            (opensmtpd-maildir-configuration->string method)])
+     ;; FIXME/TODO support specifying alias file:/path/to/alias-file  ?
+     ;; I do not think that is something that I can do...
+     (variable->string alias #:append "alias <\"" #:postpend "\"> ")
+     (variable->string ttl #:append "ttl ")
+     (variable->string user #:append "user ")
+     (variable->string userbase #:append "userbase <\"" #:postpend "\"> ")
+     (variable->string virtual #:append "virtual <" #:postpend "> ")
+     (variable->string wrapper #:append "wrapper "))))
+
+;; this function turns both opensmtpd-action-local-delivery-configuration and
+;; opensmtpd-action-relay-configuration into strings.
+(define (opensmtpd-action->string record)
+  (string-append "action "
+                 (cond [(opensmtpd-action-local-delivery-configuration? record)
+                        (opensmtpd-action-local-delivery-configuration->string record)]
+                       [(opensmtpd-action-relay-configuration? record)
+                        (opensmtpd-action-relay-configuration->string record)])
+                 " \n"))
+
+;; this turns option records found in <opensmtpd-match-configuration> into strings.
+(define* (opensmtpd-option-configuration->string record
+                                                 #:key
+                                                 (space-after-! #f))
+  (let ([not (opensmtpd-option-configuration-not record)]
+        [option (opensmtpd-option-configuration-option record)]
+        [regex (opensmtpd-option-configuration-regex record)]
+        [data (opensmtpd-option-configuration-data record)])
+    (string-append
+     (if not
+         (if space-after-!
+             "! "
+             "!")
+         "")
+     option " "
+     (if regex
+         "regex "
+         "")
+     (if data
+         (if (opensmtpd-table-configuration? data)
+             (string-append "<" (opensmtpd-table-configuration-name data) "> ")
+             (string-append data " "))
+         ""))))
+
+(define (opensmtpd-match-configuration->string record)
+  (string-append "match "
+                 (let* ([action (opensmtpd-match-configuration-action record)]
+                        [name (cond [(opensmtpd-action-relay-configuration? action)
+                                     (opensmtpd-action-relay-configuration-name action)]
+                                    [(opensmtpd-action-local-delivery-configuration? action)
+                                     (opensmtpd-action-local-delivery-configuration-name action)]
+                                    [else 'reject])]
+                        [options (opensmtpd-match-configuration-options record)])
+                   (string-append
+                    (if options
+                        (apply string-append
+                               (map opensmtpd-option-configuration->string options))
+                        "")
+                    (if (string? name)
+                        (string-append "action " "\"" name "\" ")
+                        "reject ")
+                    "\n"))))
+
+(define (opensmtpd-ca-configuration->string record)
+  (string-append "ca " (opensmtpd-ca-configuration-name record) " "
+                 "cert \"" (opensmtpd-ca-configuration-file record) "\"\n"))
+
+(define (opensmtpd-pki-configuration->string record)
+  (let ([domain (opensmtpd-pki-configuration-domain record)]
+        [cert (opensmtpd-pki-configuration-cert record)]
+        [key (opensmtpd-pki-configuration-key record)]
+        [dhe (opensmtpd-pki-configuration-dhe record)])
+    (string-append "pki " domain " " "cert \"" cert "\" \n"
+                   "pki " domain " " "key \"" key "\" \n"
+                   (if dhe
+                       (string-append
+                        "pki " domain " " "dhe " dhe "\n")
+                       ""))))
+
+(define (generate-filter-chain-name list-of-filters)
+  (string-drop-right (apply string-append
+                            (flatten
+                             (map (lambda (filter)
+                                    (list
+                                     (if (opensmtpd-filter-configuration? filter)
+                                         (opensmtpd-filter-configuration-name filter)
+                                         (opensmtpd-filter-phase-configuration-name filter))
+                                     "-"))
+                                  list-of-filters)))
+                     1))
+
+;; this procedure takes in a list of <opensmtpd-filter-configuration> and <opensmtpd-filter-phase-configuration>,
+;; returns a string of the form:
+;; filter "uniquelyGeneratedName" chain chain { "filter-name", "filter-name2" [, ...]}
+(define (opensmtpd-filter-chain->string list-of-filters)
+  (string-append "filter \""
+                 (generate-filter-chain-name list-of-filters)
+                 "\" "
+                 "chain {"
+                 (string-drop-right
+                  (apply string-append
+                         (flatten
+                          (map (lambda (filter)
+                                 (list
+                                  "\""
+                                  (if (opensmtpd-filter-configuration? filter)
+                                      (opensmtpd-filter-configuration-name filter)
+                                      (opensmtpd-filter-phase-configuration-name filter))
+                                  "\", "))
+                               list-of-filters))
+                         ) 2)
+                 "}\n"))
+
+(define (opensmtpd-filter-phase-configuration->string record)
+  (let ([name (opensmtpd-filter-phase-configuration-name record)]
+        [phase (opensmtpd-filter-phase-configuration-phase record)]
+        [decision (opensmtpd-filter-phase-configuration-decision record)]
+        [options (opensmtpd-filter-phase-configuration-options record)]
+        [message (opensmtpd-filter-phase-configuration-message record)]
+        [value (opensmtpd-filter-phase-configuration-value record)])
+    (string-append "filter "
+                   "\"" name "\" "
+                   "phase " phase " "
+                   "match "
+                   (apply string-append ; turn the options into a string
+                          (flatten
+                           (map (lambda (option)
+                                  (opensmtpd-option-configuration->string option #:space-after-! #f))
+                                options)))
+                   " "
+                   decision " "
+                   (if (string-in-list? decision (list "reject" "disconnect"))
+                       (string-append "\"" message "\"")
+                       "")
+                   (if (string=? "rewrite" decision)
+                       (string-append "rewrite " (number->string value))
+                       "")
+                   "\n")))
+
+;; filters elements may be <opensmtpd-filter-configuration>, <opensmtpd-filter-phase-configuration>,
+;; and lists that look like (list (opensmtpd-filter-configuration...) (opensmtpd-filter-phase-configuration ...)
+;; ...)
+;; this function converts it to a string.
+;; Consider if a user passed in a valid <opensmtpd-configuration>, whose total valid filters
+;; so that (get-opensmtpd-filters (opensmtpd-configuration)) returns
+;; look like this: (we will call this list "total filters"):
+;; (list (opensmtpd-filter
+;;         (name "rspamd")
+;;         (proc "rspamd"))
+;;       (list (opensmtpd-filter-phase-configuration ; this is a listen-on, with a filter-chain.
+;;               (name "dkimsign")
+;;               ...)
+;;               (opensmtpd-filter
+;;                 (name "rspamd")
+;;                 (proc "rspamd"))))
+;;
+;; did you notice that filter "rspamd" is listed twice?  How do you make sure that it is NOT
+;; printed twice in smtpd.conf?
+;; 1st flatten "total filters", then remove its duplicates.  Then print all of those filters.
+;; 2nd now we go through "total filters", and we only print the non-filter-chains.
+(define (opensmtpd-filters->string filters)
+  ;; first display the unique <opensmtpd-filter-configuration>s. and <opensmtpd-filter-phase-configuration>s.
+  ;; to do this: flatten filters, then remove duplicates.
+  (string-append
+   (apply string-append
+          (map (lambda (filter)
+                 (cond ((opensmtpd-filter-phase-configuration? filter)
+                        (opensmtpd-filter-phase-configuration->string filter))
+                       (else            ; you are a <opensmtpd-filter-configuration>
+                        (string-append "filter "
+                                       "\"" (opensmtpd-filter-configuration-name filter) "\" "
+                                       (if (opensmtpd-filter-exec filter)
+                                           "proc-exec "
+                                           "proc ")
+                                       "\"" (opensmtpd-filter-configuration-proc filter) "\""
+                                       "\n"))))
+               (delete-duplicates (flatten filters))))
+   ;; now we have to print the filter chains.
+   (apply string-append
+          (remove boolean?
+                  (map (lambda (filter)
+                         (cond ((list? filter)
+                                (opensmtpd-filter-chain->string filter))
+                               (else    ; you are a <opensmtpd-filter-configuration>
+                                #f)))
+                       filters)))))
+
+(define (opensmtpd-configuration-listen->string string)
+  (string-append
+   "include \"" string "\"\n"))
+
+(define (opensmtpd-configuration-srs->string record)
+  (let ([key (opensmtpd-srs-configuration-key record)]
+        [backup-key (opensmtpd-srs-configuration-backup-key record)]
+        [ttl-delay (opensmtpd-srs-configuration-ttl-delay record)])
+    (string-append
+     (variable->string key #:append "srs key " #:postpend "\n")
+     (variable->string backup-key #:append "srs key backup " #:postpend "\n")
+     (variable->string ttl-delay #:append "srs ttl " #:postpend "\n")
+     "\n")))
+
+;; TODO make sure all options here work!  I just fixed limit-max-rcpt!
+(define (opensmtpd-smtp-configuration->string record)
+  (let ([ciphers (opensmtpd-smtp-configuration-ciphers record)]
+        [limit-max-mails (opensmtpd-smtp-configuration-limit-max-mails record)]
+        [limit-max-rcpt (opensmtpd-smtp-configuration-limit-max-rcpt record)]
+        [max-message-size (opensmtpd-smtp-configuration-max-message-size record)]
+        [sub-addr-delim (opensmtpd-smtp-configuration-sub-addr-delim record)])
+    (string-append
+     (variable->string ciphers #:append "smtp ciphers " #:postpend "\n")
+     (variable->string limit-max-mails #:append "smtp limit max-mails " #:postpend "\n")
+     (variable->string limit-max-rcpt #:append "smtp limit max-rcpt " #:postpend "\n")
+     (variable->string max-message-size #:append "smtp max-message-size " #:postpend "\n")
+     (variable->string sub-addr-delim #:append "smtp sub-addr-delim " #:postpend "\n")
+     "\n")))
+
+(define (opensmtpd-configuration-queue->string record)
+  (let ([compression (opensmtpd-queue-configuration-compression record)]
+        [encryption (opensmtpd-queue-configuration-encryption record)]
+        [ttl-delay (opensmtpd-queue-configuration-ttl-delay record)])
+    (string-append
+     (if compression
+         "queue compression\n"
+         "")
+     (if encryption
+         (string-append
+          "queue encryption "
+          (if (not (boolean? encryption))
+              encryption
+              "")
+          "\n")
+         "")
+     (if ttl-delay
+         (string-append "queue ttl" ttl-delay "\n")
+         ""))))
+
+;; build a list of <opensmtpd-action> from
+;; opensmtpd-configuration-matches, which is a list of <opensmtpd-match-configuration>.
+;; Each <opensmtpd-match-configuration> has a fieldname 'action', which accepts an <opensmtpd-action>.
+(define (get-opensmtpd-actions record)
+  (define opensmtpd-actions
+    (let loop ([list (opensmtpd-configuration-matches record)])
+      (if (null? list)
+          '()
+          (cons (opensmtpd-match-configuration-action (car list))
+                (loop (cdr list))))))
+  (delete-duplicates (append opensmtpd-actions)))
+
+;; build a list of opensmtpd-pki-configurations from
+;; opensmtpd-configuration-listen-ons and
+;; get-opensmtpd-actions
+(define (get-opensmtpd-pki-configurations record)
+  ;; TODO/FIXME/maybe/wishlist could get-opensmtpd-actions -> NOT have an opensmtpd-action-relay-configuration?
+  ;; I think so.  And if it did NOT have a relay configuration, then action-pkis would be '() when
+  ;; it needs to be #f.  because if the opensmtpd-configuration has NO pkis, then this function will
+  ;; return '(), when it should return #f.  If it returns '(), then opensmtpd-configuration-fieldname->string will
+  ;; print the string "\n" instead of ""
+  (define action-pkis
+    (let loop1 ([list (get-opensmtpd-actions record)])
+      (if (null? list)
+          '()
+          (if (and (opensmtpd-action-relay-configuration? (car list))
+                   (opensmtpd-action-relay-configuration-pki (car list)))
+              (cons (opensmtpd-action-relay-configuration-pki (car list))
+                    (loop1 (cdr list)))
+              (loop1 (cdr list))))))
+  ;; FIXME/TODO/maybe/wishlist
+  ;; this could be #f aka left blank. aka there are no listen-ons records with pkis.
+  ;; aka there are no lines in the configuration like:
+  ;; listen on eth0 tls pki smtp.gnucode.me in that case the smtpd.conf will have an extra "\n"
+  (define listen-on-pkis
+    (let loop2 ([list (opensmtpd-configuration-listen-ons record)])
+      (if (null? list)
+          '()
+          (if (opensmtpd-listen-on-configuration-pki (car list))
+              (cons (opensmtpd-listen-on-configuration-pki (car list))
+                    (loop2 (cdr list)))
+              (loop2 (cdr list))))))
+  (delete-duplicates (append action-pkis listen-on-pkis)))
+
+;; takes in a <opensmtpd-configuration> and returns a list whose elements are <opensmtpd-filter-configuration>,
+;; <opensmtpd-filter-phase-configuration>, and a filter-chain.
+;; It returns a list of <opensmtpd-filter-configuration> and/or <opensmtpd-filter-phase-configuration>
+;; here's an example of what this procedure might return:
+;; (list (opensmtpd-filter-configuration...) (opensmtpd-filter-phase-configuration ...)
+;;       (openmstpd-filter ...) (opensmtpd-filter-phase-configuration ...)
+;;       ;; this next list is a filter-chain.
+;;       (list (opensmtpd-filter-phase-configuration ...) (opensmtpd-filter-configuration...)))
+;;
+;; This procedure handles filter chains a little odd.
+(define (get-opensmtpd-filters record)
+  (define list-of-listen-on-records (if (opensmtpd-configuration-listen-ons record)
+                                        (opensmtpd-configuration-listen-ons record)
+                                        '()))
+
+  (define listen-on-socket-filters
+    (if (opensmtpd-listen-on-socket-configuration-configuration-filters (opensmtpd-configuration-listen-on-socket record))
+        (opensmtpd-listen-on-socket-configuration-configuration-filters (opensmtpd-configuration-listen-on-socket record))
+        '()))
+
+    (delete-duplicates
+     (append (remove boolean?
+                     (map-in-order (lambda (listen-on-record) ; get the filters found in the <listen-on-record>s
+                                     (if (and (opensmtpd-listen-on-configuration-filters listen-on-record)
+                                              (= 1 (length (opensmtpd-listen-on-configuration-filters
+                                                            listen-on-record))))
+                                         (car (opensmtpd-listen-on-configuration-filters listen-on-record))
+                                         (opensmtpd-listen-on-configuration-filters listen-on-record)))
+                                   list-of-listen-on-records))
+             listen-on-socket-filters)))
+
+(define (flatten . lst)
+  "Return a list that recursively concatenates all sub-lists of LST."
+  (define (flatten1 head out)
+    (if (list? head)
+        (fold-right flatten1 out head)
+        (cons head out)))
+  (fold-right flatten1 '() lst))
+
+;; This function takes in a record, or list, or anything, and returns
+;; a list of <opensmtpd-table-configuration>s assuming the thing you passed into it had
+;; any <opensmtpd-table-configuration>s.
+;;
+;; is object record? call func on it's fieldnames
+;; is object list? loop through it's fieldnames calling func on it's records
+;; is object #f or string? or '()? -> #f
+(define (get-opensmtpd-tables value)
+  (delete-duplicates
+   (remove boolean? (flatten ;; turn (list '(1) '(2 '(3))) -> '(1 2 3)
+               (cond ((opensmtpd-table-configuration? value)
+                      value)
+                     ((record? value)
+                      (let* ([record-type (record-type-descriptor value)]
+                             [list-of-record-fieldnames (record-type-fields record-type)])
+                        (map (lambda (fieldname)
+                               (get-opensmtpd-tables ((record-accessor record-type fieldname) value)))
+                             list-of-record-fieldnames)))
+                     ((and (list? value) (not (null? value)))
+                      (map get-opensmtpd-tables value))
+                     (else #f))))))
+
+(define (opensmtpd-configuration-fieldname->string record fieldname-accessor record->string)
+  (if (fieldname-accessor record)
+      (begin
+        (string-append
+         (list-of-records->string (fieldname-accessor record) record->string) "\n"))
+      ""))
+
+(define (list-of-records->string list-of-records record->string)
+  (string-append
+   (cond [(not (list? list-of-records))
+          (record->string list-of-records)]
+         [else
+          (let loop ([list list-of-records])
+            (if (null? list)
+                ""
+                (string-append
+                 (record->string (car list))
+                 (loop (cdr list)))))])))
+
+
+;; FIXME/TODO should I use format here srfi-28 ?
+;; web.scm nginx does a (format #f "string" "another string")
+;; this could be a list like (list (file-append opensmtpd-dkimsign "/libexec/filter") "-d gnucode.me -s /path/to/selector.cert")
+;; Then opensmtpd-configuration->mixed-text-file could be rewritten to be something like
+;; (mixed-text-file (eval `(string-append (opensmtpd-configuration-fieldname->string ...)) (gnu services mail)))
+(define (opensmtpd-configuration->mixed-text-file record)
+  ;; should I use this named let, or should I give this a name, or not use it at all...
+  ;; eg: (write-all-fieldnames (list (cons fieldname fieldname->string) (cons fieldname2 fieldname->string)))
+  ;; (let loop ([list (list (cons opensmtpd-configuration-includes (lambda (string)
+  ;;                                                                 (string-append
+  ;;                                                                  "include \"" string "\"\n")))
+  ;;                        (cons opensmtpd-configuration-smtp opensmtpd-smtp->string)
+  ;;                        (cons opensmtpd-configuration-srs opensmtpd-srs->string))])
+  ;;   (if (null? list)
+  ;;       ""
+  ;;       (string-append (opensmtpd-configuration-fieldname->string record
+  ;;                                                                 (caar list)
+  ;;                                                                 (cdar list))
+  ;;                      (loop (cdr list)))))
+
+  ;;(mixed-text-file "opensmtpd.conf")
+  (string-append
+   ;; write out the includes
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-includes
+                                              opensmtpd-configuration-listen->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-bounce
+                                              (lambda (%bounce)
+                                                (if %bounce
+                                                    (list-of-strings->string %bounce)
+                                                    "")))
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-smtp
+                                              opensmtpd-smtp-configuration->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-srs
+                                              opensmtpd-configuration-srs->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-queue
+                                              opensmtpd-configuration-queue->string)
+   ;; write out the mta-max-deferred
+   (opensmtpd-configuration-fieldname->string
+    record opensmtpd-configuration-mta-max-deferred
+    (lambda (var)
+      (string-append "mta max-deferred "
+                     (number->string (opensmtpd-configuration-mta-max-deferred record)) "\n")))
+   ;;write out all the tables
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-tables opensmtpd-table-configuration->string)
+   ;; TODO should I change the below line of code into these two lines of code?
+   ;;(opensmtpd-configuration-fieldname->string record get-opensmtpd-filters-and-filter-phases opensmtpd-filter-and-filter-phase->string)
+   ;;(opensmtpd-configuration-fieldname->string record get-opensmtpd-filter-chains opensmtpd-filter-chain->string)
+   ;; write out all the filters
+   (opensmtpd-filters->string (get-opensmtpd-filters record))
+   ;; write out all the cas
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-cas opensmtpd-ca-configuration->string)
+   ;; write out all the pkis
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-pki-configurations opensmtpd-pki-configuration->string)
+   ;; write all of the listen-on-records
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-listen-ons
+                                              opensmtpd-listen-on-configuration->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-listen-on-socket
+                                              opensmtpd-listen-on-socket-configuration->string)
+   ;; write all the actions
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-actions
+                                              opensmtpd-action->string)
+   ;; write all of the matches
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-matches opensmtpd-match-configuration->string)))
+
 
 (define %default-opensmtpd-config-file
   (plain-file "smtpd.conf" "