thisI'll second the need for better documentation, especially examples.
In my case, I managed to set up email functionality with AWS SES, but it took some doing. That's not all down to XF though due to the need to learn how SES works and then to get AWS to take my account out of the sandbox required me to make a written case for it, then having to wait for approval. It felt like a completed challenge at the end of it, lol.
What i used to do with email addresses was put my own in, but they'd bounce.
So i started using the emails from my Cpanel.
No issues with the emails now.
If you're going to use those free email addresses make sure they're valid and verfied.