Some of our customers use one of these Barracuda "appliances" to filter mail (no snarky remarks, please... not my call!).
My questions are 2: 1) IF pipelining were being used, would we see the commands in a different order? I.e., when Postfix sends a copy of a transcript like this in a DSN, does it match the In / Out lines so that the commands match up, or will it send it in the *exact* order given? In other words, if the server is using pipelining, would we see: In: MAIL FROM:<sen...@bogus.example.com> In: RCPT TO:<recipi...@hostname.example.edu> In: DATA Out: 250 2.1.0 Ok Out: 451 4.3.0 <recipi...@hostname.example.edu>: Temporary lookup failure Out: 554 5.5.1 Error: no valid recipients 2) I have faith that Postfix is doing the right thing and that the Barracuda possibly is not; my reading is that by not evaluating the response to RCPT TO before the response from DATA, they're not following RFC 2920; am I wrong? > Out: 220 hostname.example.edu ESMTP Postfix > In: EHLO barracuda.example.edu > Out: 250-hostname.example.edu > Out: 250-PIPELINING > Out: 250-SIZE 50000000 > Out: 250-ETRN > Out: 250-STARTTLS > Out: 250-AUTH PLAIN LOGIN > Out: 250-ENHANCEDSTATUSCODES > Out: 250-8BITMIME > Out: 250 DSN > In: MAIL FROM:<sen...@bogus.example.com> SIZE=8982 > Out: 250 2.1.0 Ok > In: RCPT TO:<recipi...@hostname.example.edu> > Out: 451 4.3.0 <recipi...@hostname.example.edu>: Temporary lookup failure > In: DATA > Out: 554 5.5.1 Error: no valid recipients > In: RSET To me, this seems like broken behavior on the part of the smtp client (i.e., the Barracuda). w
