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

Mark Sapiro mark at msapiro.net
Thu May 16 19:19:16 CEST 2013

On 05/16/2013 01:48 AM, Jan Lausch wrote:
> Abstract:
> Some MUAs send picture-attachments not seperated by MIME-delimiters, but by "begin" and "end". Mailman adding the list footer with a MIME-delimiter breaks these mails.

This is a pre-MIME uuencoded attachment. Mailman does not understand
that the uuencoded data is an "attachment". To Mailman, it is just part
of the plain text message body.

However, I don't understand why adding msg_footer to the body would
"break" the mail. Mailman should not be changing anything in the body
between the begin and end delimiters so the uuencoded data chould be intact.

> Obviously the jpeg isn't seperated by the delimiter here even though the delimiter is introduced in the header but instead the picture only has "begin" and "end".
> I'm a bit confused: is "begin" and "end" a replacement for a MIME-delimiter?

No. It is an obsolete method of adding a uuencoded file to an email
message and predates MIME.

> Is that a correct MIME-set? 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?

> Does anyone have an idea on what to do?

Tell your user to upgrade to a MIME compliant MUA.

> 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.

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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