On Thu, Apr 17, 2014 at 01:27:23AM +0900, Stephen J. Turnbull wrote: > There are several possibilities. One is that DMARC doesn't define the > semantics of "reject". (Why doesn't that surprise me?) Here's what > they say: > > 15.4. Rejecting Messages > > This proposal calls for rejection of a message during the SMTP > session under certain circumstances. This is typically done in one > of two ways: > > o Full rejection, wherein the SMTP server issues a 5xy reply code > as an indication to the SMTP client that the transaction failed; > the SMTP client is then responsible for generating notification > that delivery failed (see Section 4.2.5 of [SMTP]). > > o A "silent discard", wherein the SMTP server returns a 2xy reply > code implying to the client that delivery (or, at least, relay) > was successfully completed, but then simply discarding the > message with no further action. > > Each of these has a cost. For instance, a silent discard may > prevent "backscatter" (the annoying generation of delivery failure > reports, which go back to the RFC5321.MailFrom address, about > messages that were fraudulently generated), but effectively means > the SMTP server has to be programmed to give a false result, which > can confound external debugging efforts.
They should have allowed/defined a new 2xy code that could be returned, eg 253 which means ''Mail accepted but will be discarded''. So a simple sending MTA could just look at the initial '2' and think 'job done', a more complex one could note that the receipt wasn't quite right. However: it still means that some people on mail lists occasionally don't get stuff - this will cause confusion at best or could be dangerous (if the mail list has a critical function). -- Alain Williams Linux/GNU Consultant - Mail systems, Web sites, Networking, Programmer, IT Lecturer. +44 (0) 787 668 0256 http://www.phcomp.co.uk/ Parliament Hill Computers Ltd. Registration Information: http://www.phcomp.co.uk/contact.php #include <std_disclaimer.h> ------------------------------------------------------ Mailman-Users mailing list Mailman-Users@python.org https://mail.python.org/mailman/listinfo/mailman-users Mailman FAQ: http://wiki.list.org/x/AgA3 Security Policy: http://wiki.list.org/x/QIA9 Searchable Archives: http://www.mail-archive.com/mailman-users%40python.org/ Unsubscribe: https://mail.python.org/mailman/options/mailman-users/archive%40jab.org
