I still have to apply Catucci's patch (or a modification of) after every Ubuntu installation or upgrade.  Otherwise, I get

  ...
  File "/usr/lib/python2.7/smtplib.py", line 752, in __init__
    SMTP.__init__(self, host, port, local_hostname, timeout)
  File "/usr/lib/python2.7/smtplib.py", line 239, in __init__
    (code, msg) = self.connect(host, port)
  File "/usr/lib/python2.7/smtplib.py", line 295, in connect
    self.sock = self._get_socket(host, port, self.timeout)
  File "/usr/lib/python2.7/smtplib.py", line 757, in _get_socket
    new_socket = socket.create_connection((host, port), timeout)
  File "/usr/lib/python2.7/socket.py", line 571, in create_connection
    raise err
socket.error: [Errno 111] Connection refused

But isn't it that #4066 should have solved the critical part this issue pair 4066/4470?