factors out postfix

mail-server/postfix.nix

@@ -0,0 +1,25 @@
+#  nixos-mailserver: a simple mail server
+#  Copyright (C) 2016  Robin Raymond
+#
+#  This program is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program. If not, see <http://www.gnu.org/licenses/>
+
+{ config, pkgs, ... }:
+{
+  services.postfix = {
+    enable = true;
+    networksStyle = "host";
+    mapFiles."valias" = valias_file;
+    mapFiles."vaccounts" = vaccounts_file; 
+  };
+}