On Tue, Jul 07, 2020 at 03:15:22AM +0000, Sebby, Brian A. wrote: > In our environment, we have two Postfix mail servers where server1 > will forward some messages to server2. We first upgraded server1 to > 3.3.1, and then later upgraded server2, but I found that Postfix > didn’t start sending the “too many hops” messages to postmaster until > we upgraded server2 to 3.3.1.
The cause is a TLS certificate misconfiguration on server2, see below. > 2bounce_notice_recipient = postmaster > bounce_notice_recipient = postmaster > delay_notice_recipient = postmaster > error_notice_recipient = postmaster > notify_classes = resource, software That said, my recommendation is to avoid all postmaster notices, with bounces going only to senders, and problems found by analysing logs. Hence: notify_classes = Creating a flood of postmaster notices can exacerbate congestion. > Out: 220 server1 ESMTP Postfix > In: EHLO server1 > Out: 250-server1 > Out: 250-PIPELINING > Out: 250-SIZE 1024000000 > Out: 250-ETRN > Out: 250-STARTTLS > Out: 250-ENHANCEDSTATUSCODES > Out: 250-8BITMIME > Out: 250-DSN > Out: 250 SMTPUTF8 > In: STARTTLS > Out: 454 4.7.0 TLS not available due to local problem This qualifies the session as having a "software" error. > In: MAIL FROM:<address@that-has-too-many-hops> SIZE=26223 > BODY=8BITMIME > Out: 250 2.1.0 Ok > In: RCPT TO:<address@server2> > ORCPT=rfc822;address@server2 NOTIFY=NEVER > Out: 250 2.1.5 Ok > In: DATA > Out: 354 End data with <CR><LF>.<CR><LF> > Out: 554 5.4.0 Error: too many hops > In: QUIT > Out: 221 2.0.0 Bye The subsequent too many hops problem (it appears you also have mail loops) is then in scope for postmaster notification. - Fix your TLS configuration, or disable TLS. - Fix the mail loops. -- Viktor.