[mailto:owner-ietf-smtp(_at_)mail(_dot_)imc(_dot_)org] On Behalf Of John
Sent: Tuesday, October 11, 2011 9:21 PM
Subject: Re: We need an IETF BCP for GREY LISTING
I really don't see anything to fix.
As far as I know, SMTP has always been a best-effort retry mechanism. It's
certainly convenient and cheap, but given the Wild West nature of Internet
messaging, I'm not so sure I buy the "timely delivery" argument either. Given
the widely deployed and varied abuse countermeasures out there, greylisting
being only one of them, highly important stuff should probably find another
transport method if arbitrary delay is unacceptable.
Knowing when to retry would be an optimization, but I haven't seen much
evidence that its absence is a real pain point worth spinning up an SMTP
extension of some kind.
A BCP about greylisting seems to be a fine thing to do, however.