Setting up Outgoing ONLY SMTP Server on Ubuntu Server 24.04

I’m attempting to run a program that makes use of an outgoing SMTP server to send me notifications if something is amiss. It’s similar to an email being sent to you if an update doesn’t go as expected in the “unattended-upgrade” package in Ubuntu.

What I don’t understand is how to set up the SMTP server. It doesn’t need to RECEIVE mail, just send to a personal email address. What I started with is postfix, but I’m certainly open to other suggestions.

Thanks in advance for your help!

-Andre