Email notifications suddenly stopped working

[sahasra]

hi ,

Would request a help on below issue:

We have nagios core 4.4.1 set up with postfix configuration and services configured which was working fine for more than 4yrs now but all of sudden, it stopped receiving email alerts for cirtical events.

There were no changes done to any of the config files or anything. We do see notifications enabled in nagios config,and for all services and hosts. Services are being monitored 24/7 and there is no "n" option configured for the notifications.

When we try "send custom host notification" from the web GUI of nagios, we are getting emails but automatic alert is happening when critical errors. Tired restarting postfix and nagios but no difference.

[sahasra]

Could someone help on this?

[cormansa]

Very strange.

do you see the alert mail on maillog (/var/log/maillog) or in syslog ?

[sahasra]

no..don't see it