[Mailman-Developers] Confirmation Messages and Modified Subject Lines

[Adrian Wells]

Hello all.  I recently discovered a concern with the manner in which
Mailman handles confirmation messages with modified subject lines.

Normally a confirmation message has a subject line such as:
confirm xxx...

It is understood that the subject line is not to be modified.  With all
confirmation subscription messages there is a note sent stating as such. 
Most recipients have no problem with this, but occasionally before a
confirmation message reaches its final destination, a spam filter, virus
scanner, mail server, etc will modify the subject line so it arrives
modified in the end users' mailbox.  For example, a tag like "[BULK]" is
added: "[BULK] confirm xxx...".  Now the end user follows the directions
and does not modify the message BUT it's already modified.

This extra text in the subject line causes problems (e.g. replies to
confirmations are not successfully processed so an user end does not
become a member of the list as he/she would expect).  However replying to
a confirmation message with a prefix like "Re:" does not seem to create
problems, for example:  Re: confirm xxx...

Would it not be better to have Mailman search for a substring, "confirm
xxx..."?  This would allow any prefixes to be ignored.

If this seems like a reasonable change, which component of Mailman is
responsible for this?  (still learning how Mailman operates).

-Adrian