[ We're veering into technical mail stuff, so this will be my last cc: to Bugtraq. ] Bret Watson writes: > Exactly... however - many mail servers _are_ misconfigured. especially > those using an external-internal relay... Preventing infinite error bouncing is not terribly difficult to begin with, and it's no more or less difficult on a boundary relay than it is on an ordinary MX relay. It takes quite a bit of work to misconfigure sendmail or qmail so that they will cause mail loops for bounce messages. Remember that the original claim was: > basically find two sites whose FW is conf'd to accept all mail and forward > it to the real mailserver. If this mailserver bounces invalid addresses > then you're on your way... And that's just wrong, as was the original suggestion that the problem is caused by delayed error notification. The problem is caused by a difficult-to-accomplish misconfiguration: either (a) the Return-Path header was incorrectly set, or (b) the bounce message was sent with a non-null envelope address. Best, daniel dulitz
This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 15:01:53 PDT