[Mailman-Users] Detecting mail with multiple From: lines

[Jay A. Sekora]

On Mon, 2011-05-23 at 11:06 -0400, Barry Warsaw wrote:
> What's the legitimate use case for multiple From headers?

Mail sent on behalf of a group, such as mail from a committee or from
the multiple authors of a paper, where you want people's individual
addresses and names exposed (or you can't create or don't want the
hassle of creating an ad-hoc email alias for the group of people).
That's what I am told users here have used it for.  That's certainly a
very rare usage, but it seems to be what the original authors of the
RFCs envisioned.  I wouldn't feel *too* bad about blocking such mail,
but since it's legal and I did discover people using it blocking it is
not my first choice.

Jay

PS -- Of course, the other question is whether the recipient's MUA is
going to do anything remotely sensible with such mail.  That's why I've
never used it myself, even in situations where it would be appropriate.
I am told that GMail, for instance, only shows the first sender.