Add subaddresses configuration

mail-server/dovecot.nix

@@ -136,6 +136,7 @@ in
         }
 
         plugin {
+          reipient_delmiter = +
           sieve_plugins = sieve_imapsieve sieve_extprograms
           sieve = file:/var/sieve/%u/scripts;active=/var/sieve/%u/active.sieve
           sieve_default = file:/var/sieve/%u/default.sieve

mail-server/postfix.nix

@@ -134,7 +134,7 @@ in
       ''
         # Extra Config
         mydestination =
-
+        recipient_delimiter = +
         smtpd_banner = ${fqdn} ESMTP NO UCE
         disable_vrfy_command = yes
         message_size_limit = ${builtins.toString cfg.messageSizeLimit}