We recently migrated a few of our mail servers from RHEL 6 with Postfix 2.6.6,
to RHEL 8 with Postfix 3.3.1. I noticed a change in behavior after we
upgraded, and I wondered if anyone had any insight into the change. Before,
while Postfix would send undeliverable messages from MAILER-DAEMON or other
more serious issues to postmaster, it never emailed us with minor issues like a
TLS incompatibility or for “too many hops” errors. After our server upgrades,
however, it has now started sending them.
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 notification settings have not changed on any of the servers:
server1 (PF 3.3.1):
2bounce_notice_recipient = postmaster
bounce_notice_recipient = postmaster
delay_notice_recipient = postmaster
error_notice_recipient = postmaster
notify_classes = resource, software
Old server2 (PF 2.6.6):
2bounce_notice_recipient = postmaster
bounce_notice_recipient = postmaster
delay_notice_recipient = postmaster
error_notice_recipient = postmaster
notify_classes = resource, software
New server2 (PF 3.3.1):
2bounce_notice_recipient = postmaster
bounce_notice_recipient = postmaster
delay_notice_recipient = postmaster
error_notice_recipient = postmaster
notify_classes = resource, software
Does anyone know of another setting or configuration parameter that might be
causing this? The messages we get are all of the form (masked for privacy):
From: Mail Delivery System <MAILER-DAEMON@server1>
To: Postmaster <postmaster@server1>
Subject: Postfix SMTP server: errors from server1 [123.456.123.456]
Transcript of session follows.
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
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
For other details, see the local mail logfile
Thanks,
Brian
--
Brian Sebby (se...@anl.gov<mailto:se...@anl.gov>) | Information Technology
Infrastructure
Phone: +1 630.252.9935 | Business Information Services
Cell: +1 630.921.4305 | Argonne National Laboratory
