Nagios Support Forum

I guess this is where you read the output and resolve the issues.
Asking others to read for you seems strange.

Not as far as I know. Nagios reacts to state changes. The text output is meaningless to nagios. If you want it to your plugin needs to react to different text output.

Looks like an argument to check_log or the defined command is not right. Run check_log directly from the host and get the args right.

Nagios can monitor an exchange box just fine. Just because a host is running echchange doesn't make it much different than any other host.

How do you know the trap gets to the trap interface?
Check for the trap in the snmptrapd.log and snmptt logs.
What do you see?

I'm having the same issue on RHEL 8.x...
That plugin is a perl script and it works ok as root, but not nagios. My guess is that the script is running something like mailq and that needs sudo defined as well.

I guess they changed the forum software. I reregistered w/ the same login.