diff --git a/mail-server.nix b/mail-server.nix
index fda1fff..baea4a4 100644
--- a/mail-server.nix
+++ b/mail-server.nix
@@ -60,15 +60,4 @@ in
   };
   
   # dovecot
-  # set the correct permissions for dovecot vmail folder. see
-  # http://wiki2.dovecot.org/SharedMailboxes/Permissions
-  systemd.services.dovecot2.preStart = "chmod 02770 /var/vmail";
-  services.dovecot2 = {
-    enable = true;
-    enableImap = enable_imap;
-    enablePop3 = enable_pop3;
-    mailGroup = vmail_group_name;
-    mailUser = vmail_user_name;
-    mailLocation = dovecot_maildir;
-   };
 }
diff --git a/mail-server/dovecot.nix b/mail-server/dovecot.nix
new file mode 100644
index 0000000..0a751d1
--- /dev/null
+++ b/mail-server/dovecot.nix
@@ -0,0 +1,33 @@
+#  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, ... }:
+{
+  # Set the correct permissions for dovecot vmail folder. See
+  # <http://wiki2.dovecot.org/SharedMailboxes/Permissions>. We choose
+  # to use the systemd service to set the folder permissions whenever
+  # dovecot gets started.
+  systemd.services.dovecot2.preStart = "chmod 02770 /var/vmail";
+
+  services.dovecot2 = {
+    enable = true;
+    enableImap = enable_imap;        # IMAP
+    enablePop3 = enable_pop3;        # POP3
+    mailGroup = vmail_group_name;
+    mailUser = vmail_user_name;
+    mailLocation = dovecot_maildir;  # maildir in format "/${domain}/${user}/"
+   };
+}