I faced an weird situation. We have a R740 server with idrac9 (v4.32.10.00) and OMSA 9.5.0 has been installed. The OS version is RHEL 7.7

I tried to configure email notifications using execute application with local SMTP server and without idrac9 configuration (to save one switch port).

I can successfully connected to https://localhost:1311.  After configuration, I can tested sending an email to myself on the web server and it worked, I can also received a notification while running my shell script under OS level.

But, when I unplugged one of the redundant power supply trying to simulate a scenario, the email notification didn't worked. I can found events report on the web server log and also in the /var/log/message, but there is no email events triggered and log in /var/log/maillog. 

I've been used this method on our other dell servers such as R430 with idrac8 and it worked well.

I just can't figure out what's the difference. Does G14 server with idrac9 changes the strategy for email notification? Does idrac9 setup is necessary for OMSA email notification?