Index: Lib/smtplib.py
===================================================================
--- Lib/smtplib.py	(revision 83376)
+++ Lib/smtplib.py	(working copy)
@@ -52,7 +52,7 @@
 __all__ = ["SMTPException","SMTPServerDisconnected","SMTPResponseException",
            "SMTPSenderRefused","SMTPRecipientsRefused","SMTPDataError",
            "SMTPConnectError","SMTPHeloError","SMTPAuthenticationError",
-           "quoteaddr","quotedata","SMTP"]
+           "SMTPSocketConnectError", "quoteaddr","quotedata","SMTP"]
 
 SMTP_PORT = 25
 SMTP_SSL_PORT = 465
@@ -118,6 +118,21 @@
 class SMTPConnectError(SMTPResponseException):
     """Error during connection establishment."""
 
+class SMTPSocketConnectError(SMTPConnectError):
+    """Error creating a socket during connection establishment
+
+    These exceptions are generated in some instances when there
+    is an error in the socket create call. The errno is stored in the
+    `errno' attribute of the error, and the `strerror' attribute
+    is set to the error message.
+    """
+
+    def __init__(self, code, msg):
+        self.errno = code
+        self.strerror = msg
+        self.args = (code, msg)
+
+
 class SMTPHeloError(SMTPResponseException):
     """The server refused our HELO reply."""
 
@@ -287,12 +302,17 @@
             i = host.rfind(':')
             if i >= 0:
                 host, port = host[:i], host[i+1:]
-                try: port = int(port)
-                except ValueError:
-                    raise socket.error("nonnumeric port")
         if not port: port = self.default_port
+
+        try: port = int(port)
+        except ValueError:
+          raise ValueError("nonnumeric port")
+
         if self.debuglevel > 0: print('connect:', (host, port), file=stderr)
-        self.sock = self._get_socket(host, port, self.timeout)
+        try:
+            self.sock = self._get_socket(host, port, self.timeout)
+        except socket.gaierror as msg:
+            raise SMTPSocketConnectError(msg.errno, msg.strerror)
         (code, msg) = self.getreply()
         if self.debuglevel > 0: print("connect:", msg, file=stderr)
         return (code, msg)
Index: Lib/test/test_smtplib.py
===================================================================
--- Lib/test/test_smtplib.py	(revision 83376)
+++ Lib/test/test_smtplib.py	(working copy)
@@ -262,13 +262,17 @@
                           smtp.send, 'test msg')
 
     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 testIllegalDomainName(self):
+        self.assertRaises(smtplib.SMTPSocketConnectError, smtplib.SMTP
+            , "canihaz*burger?.com")
 
+
 # test response of client to a non-successful HELO message
 @unittest.skipUnless(threading, 'Threading required for this test.')
 class BadHELOServerTests(unittest.TestCase):