From 27f1e8299b076f87119b3cbc92980773429aa17c Mon Sep 17 00:00:00 2001
From: Timotej Lazar <timotej.lazar@araneo.si>
Date: Sat, 1 Oct 2022 22:35:05 +0200
Subject: [PATCH] Add mail service config

---
 config/mail.scm | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 config/mail.scm

diff --git a/config/mail.scm b/config/mail.scm
new file mode 100644
index 0000000..48a6f28
--- /dev/null
+++ b/config/mail.scm
@@ -0,0 +1,54 @@
+(define-module (config mail)
+  #:use-module (gnu packages mail)
+  #:use-module (gnu services mail)
+  #:use-module (guix gexp)
+  #:use-module (gnu services)
+  #:use-module (services dkim-key)
+  #:export (mail-services))
+
+(define* (opensmtpd-config #:key interface domain aliases dkim-selector)
+  (define (format-aliases aliases)
+    (string-append (format #f "~:{~a: ~a\n~}\n"
+                           (cons* '("MAILER-DAEMON" "postmaster")
+                                  '("postmaster" "root")
+                                  '("hostmaster" "root")
+                                  '("webmaster" "root")
+                                  '("abuse" "root")
+                                  '("security" "root")
+                                  aliases))))
+
+  (mixed-text-file "smtpd.conf" "\
+smtp max-message-size \"1G\"
+table aliases file:" (mixed-text-file "aliases" (format-aliases aliases)) "
+
+pki " domain " cert \"/etc/letsencrypt/live/" domain "/fullchain.pem\"
+pki " domain " key \"/etc/letsencrypt/live/" domain "/privkey.pem\"
+
+filter \"dkimsign\" proc-exec \""
+    (file-append opensmtpd-filter-dkimsign "/libexec/opensmtpd/filter-dkimsign")
+    " -d " domain " -s " dkim-selector " -k /etc/dkim/" domain ".key\"
+
+listen on lo port submission mask-src filter \"dkimsign\"
+listen on " interface " tls pki " domain "
+listen on " interface " port submission tls-require pki " domain " auth mask-src filter \"dkimsign\"
+
+action \"deliver\" maildir \"%{user.directory}/mail\" alias <aliases>
+action \"relay\" relay
+
+match from any for domain \"" domain "\" action \"deliver\"
+match from any auth for any action \"relay\"
+"))
+
+(define* (mail-services #:key interface domain aliases dkim-selector)
+  (list (service dkim-key-service-type
+                 (dkim-key-configuration
+                   (domain domain)
+                   (selector dkim-selector)))
+
+        (service opensmtpd-service-type
+                 (opensmtpd-configuration
+                   (config-file
+                     (opensmtpd-config #:interface interface
+                                       #:domain domain
+                                       #:aliases aliases
+                                       #:dkim-selector dkim-selector))))))