Hi,
we have a two ISP setup and each ISP provides us with an mail relay
accessible within their networks.
So we have in our postfix configurations
relayhost = [relaying.ISP1.com]
smtp_fallback_relay = [relaying.ISP2.com]
to provide some fault tolerance. This works pretty good in case we have
problems with one of our ISPs.
Yesterday ISP1 changed the IP address of his relay. Therefore the
routing rules on the firewall didn't match any more and the packets went
down the wrong way. Consequently they were rejected by the relay:
Nov 9 08:56:03 mailhost postfix/pickup[14967]: 4D0373A2C7: uid=104
from=<XY>
Nov 9 08:56:03 mailhost postfix/cleanup[15247]: 4D0373A2C7:
message-id=<20111109075603.4D0373A2C7@mailhost>
Nov 9 08:56:03 mailhost postfix/qmgr[1496]: 4D0373A2C7:
from=<[email protected]>, size=1072, nrcpt=1 (queue active)
Nov 9 08:56:03 mailhost postfix/smtp[15249]: 4D0373A2C7:
to=<[email protected]>, orig_to=<XYZ>,
relay=relaying.ISP1.com[aa.bbb.ccc.ddd]:25, delay=0.14,
delays=0.03/0.01/0.07/0.03, dsn=5.7.1, status=bounced (host
relaying.ISP1.com[aa.bbb.ccc.ddd] said: 554 5.7.1 <[email protected]>:
Relay access denied (in reply to RCPT TO command))
Nov 9 08:56:03 mailhost postfix/bounce[15250]: 4D0373A2C7: sender
non-delivery notification: 70A193A2C8
Nov 9 08:56:03 mailhost postfix/qmgr[1496]: 4D0373A2C7: removed
So, first question is: why doesn't postfix try to deliver the mails
through the fallback relay?
Second question: Even if I had no fallback relay defined, I wouldn't
like the mails to be discarded as happened here. Is there a way I can
instruct postfix to keep the mails in his queue (at least to
maximal_queue_lifetime ), so that they can be delivered when the problem
is solved?
Postfix is running under Debian with default values, except the settings
of relayhost and smtp_fallback_relay.
Thank you for any advice,
Christian
