I think the problem that was being raised here was that past the DATA phase, if one recipient is going to receive the message and another is going to reject it, you have lost the ability to communicate this back to the sender (at least without an NDR). Thus the problem of mails disappearing into spam folder black holes is back in the multirecipient case when one is dealing with DATA and recipients have differing spam policies. - S -----Original Message----- From: Justin Shore [mailto:justin@justinshore.com] Sent: Saturday, July 05, 2008 2:05 AM To: Phil Vandry Cc: nanog@merit.edu Subject: Re: REJECT-ON-SMTP-DATA (Re: Mail Server best practices - was: Pandora's Box of new TLDs) Phil, This is a non-problem if you use the right spam filter. I mentioned CanIt earlier in the thread. It individually applies filtering rules to incoming mail and can apply different rules and take actions on a per-user basis. It handles messages with multiple recipients by feeding copies of the message into an individual user's stream where that user's settings dictate what actions are taken. A user may have an aggressive spam score or an extremely conservative score, message rejection with SpamHaus and SORBS or no DNSBLs at all, tons of custom rules and lots of bells and whistles or spam filtering disabled completely. They've already anticipated all the possible problems that have been brought up in this thread. Arrange for a demo and give it a try. I don't think you'd be disappointed. http://mailman.nanog.org/pipermail/nanog/2008-July/001884.html Justin