Where is the SMTP settings configured in icinga?

Where are the SMTP Settings in icinga?
Everything I searched is about sending notifications or customization.
I want to know how does the application know what smtp servers to use for mail transactions?
I am in the process of upgrading our mail relay and would like to know where in icinga I can configure these new smtp server related information.
Thank you.

There is no SMTP setting in Icinga 2 as it totally relies on the local MTA by using mailx command. So you have to find which solution is used on your system and how it is setup there.

It is likely that the solution is postfix as it is the default on many systems, then it would be relayhost setting in /etc/postfix/main.cf.


Thanks for the reply Dirk! got the postfix part covered. Just wasn’t sure how SMTP configurations were accomplished in Icinga as I wasn’t the one who set it up.