Why does satellite-sync fails with '--email' option?

Issue

• When --email option used with satellite-sync, it fails.

  root # satellite-sync
  11:46:51 Red Hat Satellite - live synchronization
  11:46:51    url: https://satellite.rhn.redhat.com
  11:46:51    debug/output level: 1
  11:46:55    db:  rhnuser/<password>@rhnschema
  11:46:55
  11:46:55 Retrieving / parsing channel-families data
  11:46:58 channel-families data complete
  11:46:58
  11:46:58 Retrieving / parsing product names data
  11:47:01 product names data complete
  Pushing scout configs to all monitoring scouts
  11:47:02
  11:47:02 Retrieving / parsing arches data
  11:47:04 arches data complete
  11:47:04
  11:47:04 Retrieving / parsing additional arches data
  11:47:05 additional arches data complete
  11:47:05
  11:47:05 Retrieving / parsing channel data
  +++ sending log as an email +++
  +++ sending log as an email +++
  Traceback (most recent call last):
   File "/usr/bin/satellite-sync", line 176, in <module>
     systemExit_exception(7, "SYNC ERROR: attempting to display as much information as possible:", e)
   File "/usr/bin/satellite-sync", line 126, in systemExit_exception
     satsync.sendMail(forceEmail=1)
   File "/usr/lib/python2.6/site-packages/spacewalk/satellite_tools/satsync.py", line 376, in sendMail
     rhnMail.send(headers, body, sender=sndr)
   File "/usr/lib/python2.6/site-packages/spacewalk/common/rhnMail.py", line 55, in send
     server = smtplib.SMTP('localhost')
   File "/usr/lib64/python2.6/smtplib.py", line 239, in __init__
     (code, msg) = self.connect(host, port)
   File "/usr/lib64/python2.6/smtplib.py", line 295, in connect
     self.sock = self._get_socket(host, port, self.timeout)
   File "/usr/lib64/python2.6/smtplib.py", line 273, in _get_socket
     return socket.create_connection((port, host), timeout)
   File "/usr/lib64/python2.6/socket.py", line 567, in create_connection
     raise error, msg
  socket.error: [Errno 97] Address family not supported by protocol