[Mailman-Users] mails without MIME delimiter break when sent through mailman

[Stephen J. Turnbull]

Mark Sapiro writes:
 > On 05/16/2013 01:48 AM, Jan Lausch wrote:

 > > Is that a correct MIME-set?

As Mark says, it's conformant to MIME in that a MIME conforming MUA is
perfectly happy to process that encoded file as part of the message
body's text, completely oblivious to the fact that it's really an
image.

It's incorrect in that it doesn't do what the users expect.

 > > But still this malformatted mail does work if sent directly to
 > > recipient (not via mailman) and still does NOT have the delimiter
 > > then. It only breaks when sent via mailman.  Obviously things
 > > stop working when mailman adds the delimiter consisting the
 > > msg_footer.
 > 
 > Which is the part I don't understand. Mailman's msg_footer comes after
 > the "end" of the uuencoded data, so what's the problem?

I would guess that some recipient MUA readded uuencode support only as
a bug fix without really thinking about what they were doing, and it's
only supported at the end of a message in the MIME trailer.

 > > Does anyone have an idea on what to do?
 > 
 > Tell your user to upgrade to a MIME compliant MUA.

If the MUA *sending* uuencoded JPEGs is really a Microsoft product, I
guess there is a switch in the user preferences that allows sending
files as "MIME" bodies rather than with "uuencode".  Ask the user to
flip the switch; they're not doing anybody any favors by using
uuencode nowadays.

 > > Can I perhaps prevent mailman adding a footer if I leave
 > > "msg_footer" empty?  Is it still added (empty) or not at all?
 > 
 > Yes, msg_footer can be empty and Mailman won't add anything.

N.B. IIRC, it has to be *empty*, not blank.  Make sure there's no
remnant of whitespace there, either.