diff -r dc3afbee4ad1 Lib/smtplib.py
--- a/Lib/smtplib.py	Mon Jun 02 01:32:23 2014 -0700
+++ b/Lib/smtplib.py	Tue Jun 03 11:22:05 2014 +0300
@@ -239,7 +239,11 @@
         self.source_address = source_address
 
         if host:
-            (code, msg) = self.connect(host, port)
+            try:
+                (code, msg) = self.connect(host, port)
+            except SMTPResponseException:
+                self.close()
+                raise
             if code != 220:
                 raise SMTPConnectError(code, msg)
         if local_hostname is not None: