Nagios Support Forum

this afternoon there's a cpu warning/critical alert, but didn't receive email notification. the other services warning/critical alert got email notification as expected. the administrator checked the contact found it's empty, what could be the problem?(he had added the contact manually)

When you say that the administrator added the contact manually, did they do it through the Core Configuration Manager? Or did they edit the config files? I ask because the config files get overwritten whenever a new configuration is applied.

they edited through CCM.

the strange thing is before they manual added the contact, NagiosXI already miss sent email notification, so they had to emergent manual add contact to prevent not getting the email notification.
after that, they want to know why that it happeded?

Someone may have changed the configuration. The audit log may have some information - Admin > System Information > Audit Log.