Index: Lib/smtplib.py
===================================================================
--- Lib/smtplib.py	(revision 60977)
+++ Lib/smtplib.py	(working copy)
@@ -285,12 +285,15 @@
             i = host.rfind(':')
             if i >= 0:
                 host, port = host[:i], host[i+1:]
-                try: port = int(port)
-                except ValueError:
-                    raise socket.error, "nonnumeric port"
+
+        port = int(port)
+
         if not port: port = self.default_port
         if self.debuglevel > 0: print>>stderr, 'connect:', (host, port)
-        self.sock = self._get_socket(host, port, self.timeout)
+        try:
+            self.sock = self._get_socket(host, port, self.timeout)
+        except socket.error, msg:
+            raise SMTPConnectError(msg.errno, msg.strerror)
         (code, msg) = self.getreply()
         if self.debuglevel > 0: print>>stderr, "connect:", msg
         return (code, msg)
Index: Lib/test/test_smtplib.py
===================================================================
--- Lib/test/test_smtplib.py	(revision 60977)
+++ Lib/test/test_smtplib.py	(working copy)
@@ -93,10 +93,10 @@
         smtp.sock.close()
 
     def testNonnumericPort(self):
-        # check that non-numeric port raises socket.error
-        self.assertRaises(socket.error, smtplib.SMTP,
+        # check that non-numeric port raises ValueError
+        self.assertRaises(ValueError, smtplib.SMTP,
                           "localhost", "bogus")
-        self.assertRaises(socket.error, smtplib.SMTP,
+        self.assertRaises(ValueError, smtplib.SMTP,
                           "localhost:bogus")
 
     def testTimeoutDefault(self):