diff --git a/tests/extern.nix b/tests/extern.nix
new file mode 100644
index 0000000..e32cd4d
--- /dev/null
+++ b/tests/extern.nix
@@ -0,0 +1,68 @@
+#  nixos-mailserver: a simple mail server
+#  Copyright (C) 2016-2017  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/>
+
+import ./../../nixpkgs/nixos/tests/make-test.nix {
+
+  nodes =
+    { server = { config, pkgs, ... }:
+        {
+            imports = [
+                ./../default.nix
+            ];
+
+            mailserver = {
+              enable = true;
+              domain = "example.com";
+
+              hostPrefix = "mail";
+              loginAccounts = {
+                  user1 = {
+                      hashedPassword = "$6$/z4n8AQl6K$kiOkBTWlZfBd7PvF5GsJ8PmPgdZsFGN1jPGZufxxr60PoR0oUsrvzm2oQiflyz5ir9fFJ.d/zKm/NgLXNUsNX/";
+                  };
+              };
+
+              enableImap = true;
+            };
+        };
+      client = { config, pkgs, ... }:
+      {
+        environment.systemPackages =with pkgs; [ fetchmail ];
+      };
+    };
+
+  testScript =
+  let
+    fetchmailRc =
+    ''
+    poll SERVER with proto IMAP
+        user 'user1\@example.com' there with password 'user1' is 'root' here
+    '';
+  in
+    ''
+      startAll;
+
+      $server->waitForUnit("multi-user.target");
+      $client->waitForUnit("multi-user.target");
+
+      subtest "imap", sub {
+          $client->succeed("echo '${fetchmailRc}' > ~/.fetchmailrc");
+          $client->succeed("sed -i s/SERVER/`getent hosts server | awk '{ print \$1 }'`/g ~/.fetchmailrc");
+          $client->succeed("chmod 0700 ~/.fetchmailrc");
+          $client->succeed("cat ~/.fetchmailrc >&2");
+          $client->succeed("fetchmail -v || [ \$? -eq 1 ] >&2");
+      };
+    '';
+}
diff --git a/tests/userPassword.nix b/tests/intern.nix
similarity index 100%
rename from tests/userPassword.nix
rename to tests/intern.nix