David Bremner <david@tethera.net> writes:

> It would be a big help if you could share a message that causes the
> problem.

I've just managed to make an example that triggers the problem but that
isn't 14MB (the size of the original msg).  I'm attaching the message
below.  It contains, as an attachment, a 20KB .tgz file.

If it doesn't trigger the problem for you, I could also more closely
reproduce the procedure that triggers it by sending a message to the
list with that tgz file as an attachment.  But I am reluctant to do that
in the first instance, in case that approach does trigger the problem
for everyone reading the list emails using emacs!

( For my own reference in finding the message again: 
  notmuch search id:87d2d0uvoc.fsf@approx.mit.edu )

-Sanjoy