ned(_dot_)freed(_at_)mrochek(_dot_)com writes:
Thus far in this conversation we have one anecdotal report that
there may be some systems that botch this, and which may well refer
to some long-vanished implementation from the early days of MIME.
Link to one discussion mentions MUAs but not MTAs:
http://www.gnus.org/list-archives/ding/199907/msg00657.html
I don't know if it really was a MUA issue. I have not seen this
frequently, but I remember similar discussions. Sorry for not
providing anything more substantial.