On 2021/06/16 09:04, Xavier Beaudouin via mailop wrote: > Hello there, > > I have a setup with 2 MX : > > domain.tld mx 10 mx1.domain.tld > domain.tld mx 30 mx3.domain.tld > > For some operational reason mx3 replys all mail with a 454 which is TEMPORALY > error... : > Jun 14 23:22:55 mx3 postfix/smtpd[83891]: NOQUEUE: reject: RCPT from > mail-eopbgr50127.outbound.protection.outlook.com[40.107.5.127]: 454 4.7.1 > <[email protected]>: Relay access denied; from=<[email protected]> > to=<[email protected]> proto=ESMTP > helo=<EUR03-VE1-obe.outbound.protection.outlook.com> > > It trys about 31 times.... But they didn't had the idea to check the mx1... > which is ready for relay.
You can't tell for certain that they didn't check the mx1. Perhaps there was a network error. Sometimes route announcements don't make it to the whole world, sometimes packets to some hosts but not others end up on a broken member of a load-balanced port group. Related, note that some SMTP software doesn't fall to a lower priority MX if the higher priority one connects but rejects with temporary failure. Things work best if all listed MX that accept connections are prepared to accept mail. _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
