On Fri, 03 Mar 2006, Tomasz Ostrowski wrote: > I'm going to send a feature request to > <[EMAIL PROTECTED]>.
----- Forwarded message ----- From: Tomasz Ostrowski <[EMAIL PROTECTED]> Subject: RFE: Tempfail "data" when at least one "rcpt to" tempfailed and none accepted To: [EMAIL PROTECTED] Date: Fri, 3 Mar 2006 10:51:52 +0100 I'd like to ask for considering my proposal - that "data" requests would be temporarily rejected (4xx) instead of permanently rejected, when at least one "rcpt to" request was temporarily rejected and no "rcpt to" request was accepted. The developer or MIMEdefang milter (http://www.mimedefang.org/), "David F. Skoll" <dfs<at>roaringpenguin.com> said on its mailing list that it has implemented greylisting in a way that tempfails after "data", not after "rcpt to" command. The reasoning was: | Now, there *are* some marginal SMTP servers that fail in the | following scenario: | | C: HELO myname.domain.com | S: 250 whatever | C: MAIL FROM:<[EMAIL PROTECTED]> | S: 250 2.1.0 go ahead | C: RCPT TO:<[EMAIL PROTECTED]> | S: 451 4.7.1 greylisting; try in 2 minutes | C: DATA | S: 503 5.0.0 need RCPT! | | (and client bounces message) | | Notice that? Some marginal clients attempt a DATA even if all | RCPTs are 4xx'd. Our solution is to greylist after the DATA phase | (that is, at the ".") While this wastes bandwidth, it does keep | those marginal SMTP implementations from failing. I said that: | This could be avoided if sendmail would tempfail "data" requests if | any "rcpt to" request tempfailed and every "rcpt to" request | tempfailed or permfailed. David did not like this, because: 1. Sendmail has a right to reject after data phase, because RFC states, that at least one recipient must be accepted when a client sends "data". I agree, but it also has a right to tempfail. 2. Sendmail can assume that if a client has broken implementation which caused this failure, then every subsequent attempts will also fail, so there's no reason to tempfail. I do not agree - if there's temporary failure then it should be assumed that the conditions can change and next time there'll be no reason to tempfail. If commands are "repeated identically" then they can be successful, hence proposed 4xx response. Regards Tometzky -- ...although Eating Honey was a very good thing to do, there was a moment just before you began to eat it which was better than when you were... Winnie the Pooh ----- End forwarded message ----- _______________________________________________ NOTE: If there is a disclaimer or other legal boilerplate in the above message, it is NULL AND VOID. You may ignore it. Visit http://www.mimedefang.org and http://www.roaringpenguin.com MIMEDefang mailing list [email protected] http://lists.roaringpenguin.com/mailman/listinfo/mimedefang
