From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8) Gecko/20051111 Firefox/1.5

Description of problem:
I noticed that some footers appended by Mailman break
the encoding of quoted-printable messages. The footer
presently being appended to messages going through SF
mailing lists contains the following link:

http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click

If the message is encoded as quoted-printable, then the
'=' in the URL should be interpreted by the mail client
as starting an encoded octet (according to RFC 2045
6.7(1)). While '=76' and '=16' are valid (though
unintended) encoded octets, '=cl' is not because 'l' is
not a hex digit, and hence the message doesn't have a
valid encoding.

This causes problems for mail clients which don't know
how to handle improper quoted-printable encoding.

Aparently this has been fixed in Mailman 2.1.6, which I
see is going to be in FC5. In any case, I thought it would
be good to report this since many people will be using FC4
for a while to come.

Version-Release number of selected component (if applicable):
mailman-2.1.5-35.fc4

How reproducible:
Always

Steps to Reproduce:
1. Put an '=' in a mailman footer, followed by something in [^0-9A-Fa-f].
2. Send a quoted-printable encoded message to the list.
3. Notice that the footer isn't properly encoded when the message comes back.
  

Actual Results:  Returned message was improperly encoded.

Expected Results:  Returned message should be properly encoded.

Additional info: