Gunnar Hjalmarsson wrote:
RfC 3834 says only MAY.
Hmm.. You're right. Weird! It should at least have said
SHOULD, shouldn't it?
For a C/R system: it could try to catch bounced challenges
and delete the original mail in this case (C/R is already
utter dubious, so why not screw it up beyond repair... ;-)
For other auto-responders the same idea, catch bounces and
then do not try it again could make sense. Mailing list
subscribe / unsubscribe bots could do something smart with
this info.
It's fun to read RfC 3834,
Maybe for some definition of 'fun'. :)
Try chapter four for the funny stuff:
| A Personal or Group responder SHOULD NOT deliver a response
| to any address other than that in the Return-Path field, even
| if the Return-Path field is missing. It is better to fix the
| problem with the mail delivery system than to rely on heuristics
| to guess the appropriate destination of the response. Such
| heuristics have been known to cause problems in the past.
Bye, Frank