On Mon, Aug 04, 2008, Peter Hardy wrote: > I for one think it's perfectly cromulent. If the sender MX utilises > greylisting then it'll send back a transient failure message as distinct > from a permanent 550 failure. At that point, the receiving MX can either > assume a transient failure means it's normally a valid address and > accept the mail, or give back its own transient failure - an eye for an > eye if you like.
Yeah, apparently the misbehaviour is when the verifying server receives a 4xx due to the greylisting, and is configured to treat 4xx as a permanent failure. THAT would count as a misconfiguration, good and proper. I think it all gets amazingly awful when BOTH sides are implementing sender address verification AND greylisting. Aside from that there's the general bothersomeness of delayed mail (especially when it gets into the problem greylisting has with usually wanting to match the IP on subsequent requests) but greylisting is doing the heavy delaying in both this and its usual scenario. -Mary -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
