--- smtplib.py.orig	2017-05-17 16:48:56.993030185 -0600
+++ smtplib.py	2017-05-17 16:55:09.564272075 -0600
@@ -250,6 +250,7 @@
         if host:
             (code, msg) = self.connect(host, port)
             if code != 220:
+                self.close()
                 raise SMTPConnectError(code, msg)
         if local_hostname is not None:
             self.local_hostname = local_hostname