diff -r a765a06383af Lib/test/test_smtpd.py
--- a/Lib/test/test_smtpd.py	Mon Aug 22 18:12:39 2011 +1000
+++ b/Lib/test/test_smtpd.py	Mon Aug 22 18:41:39 2011 +1000
@@ -21,6 +21,27 @@
 # Pick a non-privileged port to bind to
 SMTP_DEFAULT_PORT = 4731
 
+class MockSMTP(SMTP):
+    '''
+    Obviously when testing delivery we don't want to get coupled
+    to a running remote SMTP server
+    '''
+    raise_on_connect = None
+    
+    def connect(self, remote_hostname, remote_port):
+        
+        if MockSMTP.raise_on_connect:
+            raise MockSMTP.raise_on_connect
+        
+        pass
+    
+    @classmethod
+    def set_raise_on_connect(cls, exc):
+        '''
+        Allow this to test both success and failure of connection
+        '''
+        MockSMTP.raise_on_connect = exc
+
 
 class DummyServer(smtpd.SMTPServer):
     def __init__(self, localaddr, remoteaddr):
@@ -304,30 +325,8 @@
         '''
         Don't go round binding to actual ports during testing
         '''
-        smtpd.socket = asyncore.socket = mock_socket    
-        
-        class MockSMTP(SMTP):
-            '''
-            Obviously when testing delivery we don't want to get coupled
-            to a running remote SMTP server
-            '''
-            raise_on_connect = None
-            
-            def connect(self, remote_hostname, remote_port):
-                
-                if MockSMTP.raise_on_connect:
-                    raise MockSMTP.raise_on_connect
-                
-                pass
-            
-            @classmethod
-            def set_raise_on_connect(cls, exc):
-                '''
-                Allow this to test both success and failure of connection
-                '''
-                MockSMTP.raise_on_connect = exc
-            
-        smtplib.SMTP = MockSMTP        
+        smtpd.socket = asyncore.socket = mock_socket            
+        smtplib.SMTP = MockSMTP
         
     def tearDown(self):
         '''
@@ -414,10 +413,59 @@
             refusingServer.process_message(peer, mailfrom, rcpttos, SAMPLE_MESSAGE_DATA)
             
             
+class MailmanProxyTest(TestCase):
+    
+    def setUp(self):
+        '''
+        Don't go round binding to actual ports during testing
+        '''
+        smtpd.socket = asyncore.socket = mock_socket    
+        smtplib.SMTP = MockSMTP        
+        
+    def tearDown(self):
+        '''
+        Leave the smtp ports as we found them
+        '''
+        asyncore.close_all()
+        asyncore.socket = smtpd.socket = socket
+        
+        smtplib.SMTP = SMTP
+        
+    def test_process_message(self):
+        
+        class MockMailmanProxy(smtpd.MailmanProxy):
+                
+            def _deliver(self, mailfrom, rcpttos, data):
+                return {}
+
+        class RefusingMailmanProxy(smtpd.MailmanProxy):
+            
+            def _deliver(self, mailfrom, rcpttos, data):
+                return "A fake refusal"        
+            
+        localaddress = ('localhost', SMTP_DEFAULT_PORT)
+        remoteaddress = ('localhost', SMTP_DEFAULT_PORT + 1)
+        theServer = MockMailmanProxy(localaddress, remoteaddress)
+        
+        # Add the X-Peer header that DebuggingServer adds
+        peer = socket.gethostbyname('localhost')
+        
+        # Send a mail from myself
+        mailfrom = 'tleeuwenburg@gmail.com'
+        
+        # To myself
+        rcpttos = 'tleeuwenburg@gmail.com'        
+        empty_message_data = ''
+        
+        # Test on plausible data
+        theServer.process_message(peer, mailfrom, rcpttos, SAMPLE_MESSAGE_DATA)
+            
+            
 def test_main():
     support.run_unittest(SMTPDServerTest, 
                          SMTPDChannelTest,
-                         PureProxyTest)
+                         PureProxyTest,
+                         MailmanProxyTest)
 
 if __name__ == "__main__":
     test_main()