Description of problem:
trying to use mail_type=multipart in config file

Version-Release number of selected component (if applicable):
svnmailer-1.0.8-3.fc7

How reproducible:
1. install svnmailer
2. add 
mail_type = multipart
to mailer.conf
3. run
/usr/bin/svn-mailer commit <path_to_repo> <revision> <path_to_config>
on my machine there was
/usr/bin/svn-mailer commit /opt/mars/svn/ 84  /opt/mars/svn/conf/mailer.conf 
  
Actual results:
[timon@swebs hooks]$ /usr/bin/svn-mailer commit /opt/mars/svn/ 84 
/opt/mars/svn/conf/mailer.conf 
One or more notifiers crashed. You may want to send the following traceback(s)
to the author:

------------------------------------------------------------------------------
Notifier: svnmailer.util.SendmailSubmitter
Revision: 84
Groups: [u'defaults']
Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/svnmailer/main.py", line 101, in run
    notifier.run()
  File "/usr/lib/python2.5/site-packages/svnmailer/notifier/_mail.py", line 62,
in run
    for mail in self.getMails():
  File "/usr/lib/python2.5/site-packages/svnmailer/notifier/_mail.py", line 83,
in getMails
    for mail in self.composeMail():
  File "/usr/lib/python2.5/site-packages/svnmailer/notifier/_multimail.py", line
163, in composeMail
    self.writeNotification()
  File "/usr/lib/python2.5/site-packages/svnmailer/notifier/_mail.py", line 96,
in writeNotification
    self.writeDiffList()
  File "/usr/lib/python2.5/site-packages/svnmailer/notifier/_multimail.py", line
221, in writeDiffList
    super(MultiMailNotifier, self).writeDiffList()
  File "/usr/lib/python2.5/site-packages/svnmailer/notifier/_text.py", line 183,
in writeDiffList
    self.writeContentDiff(change)
  File "/usr/lib/python2.5/site-packages/svnmailer/notifier/_multimail.py", line
240, in writeContentDiff
    self.diff_file_list.append(DiffDescriptor(self, tmpfile, change))
  File "/usr/lib/python2.5/site-packages/svnmailer/notifier/_multimail.py", line
629, in __init__
    enc1, enc2 = notifier.getContentEncodings(change, None)
  File "/usr/lib/python2.5/site-packages/svnmailer/notifier/_base.py", line 348,
in getContentEncodings
    from encodings import exceptions
ImportError: cannot import name exceptions

Expected results:
nothing

Additional info:
FreeBSD ports patch
http://lists.freebsd.org/pipermail/freebsd-ports-bugs/2007-October/128898.html