diff --git a/roles/mail_server/tests/test_client2.py b/roles/mail_server/tests/test_client2.py
index 4b06697c6e15cc9333ecaa4fed7f18a9fafa3787..0fb423dcab42e40e8ef857985d8763bbcf8b6e7c 100644
--- a/roles/mail_server/tests/test_client2.py
+++ b/roles/mail_server/tests/test_client2.py
@@ -22,6 +22,14 @@ def test_open_relay(Command):
     assert send.rc == no_recipients_accepted
     assert "Relay access denied" in send.stdout
 
+    send = Command('swaks --port 27 --suppress-data --to root@client1 --server parameters-mandatory')
+    assert send.rc == no_recipients_accepted
+    assert "Relay access denied" in send.stdout
+
+    send = Command('swaks --port 27 --suppress-data --to root@client1 --server parameters-optional')
+    assert send.rc == no_recipients_accepted
+    assert "Relay access denied" in send.stdout
+
 
 def test_mail_delivery(Command):
     """
@@ -243,7 +251,7 @@ def test_connectivity(Command, Sudo):
 
         for server in ["parameters-mandatory",
                        "parameters-optional"]:
-            for port in [25, 26, 587, 143, 993, 4190]:
+            for port in [25, 26, 27, 587, 143, 993, 4190]:
 
                 ping = Command('hping3 -S -p %d -c 1 %s' % (port, server))
                 assert ping.rc == 0
@@ -251,9 +259,20 @@ def test_connectivity(Command, Sudo):
 
 def test_port_forwarding(Command, Sudo):
     """
-    Tests if port forwarding is set-up correctly for submission port.
+    Tests if port forwarding is set-up correctly for additional SMTP and
+    submission ports.
     """
 
+    # Regular SMTP.
+    send = Command('swaks -tls --port 27 --to john.doe@domain1 --server parameters-mandatory')
+    assert send.rc == 0
+    assert "Ok: queued as" in send.stdout
+
+    send = Command('swaks -tls --port 27 --to john.doe@domain1 --server parameters-optional')
+    assert send.rc == 0
+    assert "Ok: queued as" in send.stdout
+
+    # Submission port.
     send = Command('swaks -tls --port 26 --auth-user john.doe@domain1 --auth-password johnpassword --to root@client1 --server parameters-mandatory')
     assert send.rc == 0
     assert "Ok: queued as" in send.stdout