[Discuss] DMARC issue, Yahoo and beyond

[Richard Pieri]

Derek Martin wrote:
> in any fashion.  Mutt properly ignored your reply-to header and did
> what I asked it to do.  It had *absolutely no effect* as I said.

With the caveat that I did not list Mutt by name but that's quibbling.
Point is, as you've experienced yourself, Mutt's behavior is not
consistent when improperly-set Reply-To fields are in play.

The reason is simple: the program is trying to deal with two conflicting
directives. The only ways for a MUA to reconcile these conflicts is to
ignore one of the two users: the original sender or the author of the
reply. Ignore the original sender and you break RFCs 822 and 2822.
Ignore the author of the reply and you annoy that user. Pick one.

Or you can pick the third option: don't insert or alter Reply-To fields.
If there is no Reply-To field then there is no conflict. If there is no
conflict then any given MUA will behave consistently for its user.

-- 
Rich P.