Starting with Python 2.5 (PYTHON_REL == 250) Exceptional Handling is built-in.

See Misc/News:
 * Exceptions are now built-in in python (LP: #111735)
    (Thanks to Daniel Gruen for providing the patch)
  * debian/control: Modify Maintainer value to match
    DebianMaintainerField spec.

mail/svnmailer doesn't account for this.

Fix: Conditionally apply this patch if PYTHON_REL >= 250

Patch obtained from:
http://launchpadlibrarian.net/8131802/svnmailer-1.0.8-python2.5.diff

Note additional of files directory and new patch file.

portlint -ACN
port looks clean.

Patch attached with submission follows:
How-To-Repeat: cvsup to a ports tree post 2.5 python default.
cd mail/svnmailer
make install

#!/bin/sh
SVNADMIN=/usr/local/bin/svnadmin
MAILER=/usr/local/bin/svn-mailer
CONFIG=/usr/local/etc/svn-mailer.conf
REPOS=/home/svn
$MAILER -d "$REPOS" -r "1" -f $CONFIG

Notifier: svnmailer.util.SplittingDecorator
Revision: 3428
Groups: [u'defaults']
Traceback (most recent call last):
  File "/usr/local/lib/python2.5/site-packages/svnmailer/main.py", line 101, in run
    notifier.run()
  File "/usr/local/lib/python2.5/site-packages/svnmailer/notifier/_mail.py", line 62, in run
    for mail in self.getMails():
  File "/usr/local/lib/python2.5/site-packages/svnmailer/notifier/_mail.py", line 83, in getMails
    for mail in self.composeMail():
  File "/usr/local/lib/python2.5/site-packages/svnmailer/notifier/_textmail.py", line 131, in composeMail
    self.writeNotification()
  File "/usr/local/lib/python2.5/site-packages/svnmailer/notifier/_mail.py", line 96, in writeNotification
    self.writeDiffList()
  File "/usr/local/lib/python2.5/site-packages/svnmailer/notifier/_text.py", line 183, in writeDiffList
    self.writeContentDiff(change)
  File "/usr/local/lib/python2.5/site-packages/svnmailer/notifier/_textmail.py", line 303, in writeContentDiff
    self.__super.writeContentDiff(change)
  File "/usr/local/lib/python2.5/site-packages/svnmailer/notifier/_text.py", line 352, in writeContentDiff
    change, enc = enc, default = default
  File "/usr/local/lib/python2.5/site-packages/svnmailer/notifier/_base.py", line 300, in dumpContent
    enc1, enc2 = self.getContentEncodings(change)
  File "/usr/local/lib/python2.5/site-packages/svnmailer/notifier/_base.py", line 348, in getContentEncodings
    from encodings import exceptions
ImportError: cannot import name exceptions