get postfix working

I still have to decide what to do with the certificate file

mail-server/postfix.nix

@@ -14,11 +14,74 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ valiases_file, vaccounts_file, ... }:
+{ mail_dir, domain, valiases }:
 
+let
+  # valiasToString :: { from = "..."; to = "..." } -> String
+  valiasToString = x: "${x.from}@${domain} ${x.to}@${domain}\n";
+
+  # valiases_postfix :: [ String ]
+  valiases_postfix = map valiasToString valiases;
+
+  # concatString :: [ String ] -> String
+  concatString = l: if l == []
+                    then ""
+                    else (builtins.head l) + (concatString (builtins.tail l));
+
+  # valiases_file :: Path
+  valiases_file = builtins.toFile "valias" (concatString valiases_postfix);
+
+  # vhosts_file :: Path
+  vhosts_file = builtins.toFile "vhosts" domain;
+in
 {
   enable = true;
   networksStyle = "host";
-  #  mapFiles."valias" = valiases_file;
+  mapFiles."valias" = valiases_file;
   #  mapFiles."vaccounts" = vaccounts_file; 
+  #  sslCert = "/etc/nixos/cert/${cert_file}";
+  #  sslKey = "/etc/nixos/cert/${key_file}";
+
+  extraConfig = 
+  ''
+
+    # Extra Config
+
+    smtpd_banner = $myhostname ESMTP NO UCE
+    smtpd_tls_auth_only = yes
+    disable_vrfy_command = yes
+    message_size_limit = 20971520
+
+    milter_rcpt_macros = i {rcpt_addr}
+
+    # virtual mail system
+    virtual_uid_maps = static:5000
+    virtual_gid_maps = static:5000
+    virtual_mailbox_base = ${mail_dir}
+    virtual_mailbox_domains = ${vhosts_file}
+    virtual_alias_maps = hash:/var/lib/postfix/conf/valias
+    virtual_transport = lmtp:unix:private/dovecot-lmtp
+
+    # sasl with dovecot
+    smtpd_sasl_type = dovecot
+    smtpd_sasl_path = private/auth
+    smtpd_sasl_auth_enable = yes
+    smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
+  '';
+
+  extraMasterConf =
+  ''
+    # Extra Config
+    #submission inet n - n - - smtpd
+    #  -o smtpd_tls_security_level=encrypt
+    #  -o smtpd_sasl_auth_enable=yes
+    #  -o smtpd_sasl_type=dovecot
+    #  -o smtpd_sasl_path=private/auth
+    #  -o smtpd_sasl_security_options=noanonymous
+    #  -o smtpd_sasl_local_domain=$myhostname
+    #  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
+    #  -o smtpd_sender_login_maps=hash:/etc/postfix/virtual
+    #  -o smtpd_sender_restrictions=reject_sender_login_mismatch
+    #  -o smtpd_recipient_restrictions=reject_non_fqdn_recipient,reject_unknown_recipient_domain,permit_sasl_authenticated,reject
+  '';
 }

mail-server/services.nix

@@ -17,13 +17,6 @@
 { mail_dir, vmail_user_name, vmail_group_name, valiases, domain, enable_imap,
 enable_pop3 }:
 
-let
-  # valiasToString :: { from = "..."; to = "..." } -> String
-  valiasToString = x: x.from + "@" + domain + " " + x.to "@" + domain + "\n";
-
-  # valias_file :: [ String ]
-  valiases_file = map valiasToString valiases;
-in
 {
   # rspamd
   rspamd = {
@@ -31,7 +24,7 @@ in
   };
 
   postfix = import ./postfix.nix {
-    valiases_file = ""; vaccounts_file = ""; #< TODO: FIX
+    inherit mail_dir domain valiases;
   };
 
   dovecot2 = import ./dovecot.nix {