On Fri, 29 Jul 2011 23:52:50 +0200, Michelle Sullivan said:
reference to bounce messages and mailing lists.) The registration email has a null return path because people will put in forged addresses and we don't want them to do that in the first place, and if they do it, we certainly don't want any auto-responder from replying or it going to a mailing list (most mailing list software prevent delivery of null return path mail to the list members) - seems the like most responsible and desired setup.. which is why I chose it.
LSoft's Listserv product does this as well - subscription confirmation messages and some other administrivia mail are sent with MAIL FROM:<> so forged subscribe requests don't generate bounces. The upshot is that if you block <> your users will never be able to subscribe to any Listserv-hosted list. There's enough sites running Listserv that it might be a bit more impact than "I can't e-mail SORBS"... I have always been amazed at how products like the Barracuda or the PIX can ship with totally broken software, and yet get enough market share to cause so much pain for the rest of us. Some days, I wonder if there's grounds for legal action - do such broken "training wheels for net admins" products constitute an attractive nuisance? ;)