Set up mail-receiver, but now site won't send any emails?

[Simon_Manning]

@ToddZ

So I guess all the troubleshooting is out the window and I have to look for a new email host that doesn’t impose that requirement.

It’s certainly not exhaustive but there are some sending service recommendations in the install documentation along with some basic information about using them in Discourse: discourse/docs/INSTALL-email.md at main · discourse/discourse · GitHub

The following topic (linked at the bottom of that document) also has information about bounce handling for those and others:

Configure VERP to handle bouncing e-mails

Setting up bounces handling Discourse uses the Variable envelope return path (VERP) technique to handle bouncing e-mails. To enable VERP, set the “reply by email address” site setting with an email address template that uses the + sign. The default of replies+%{reply_key}@discourse.example.com … works fine. If you are using your own or your company’s email server, then, that’s it Your discourse instance must be able to receive email sent to this address. This should work via POP, bu…

I use Mailgun flex plan (entirely within free allowance) myself but I know there has been confusion around their pricing and potentially things have changed for new users since I joined. The last I saw (no idea if still true), it was possible to move to flex after the trial ended, it was just incredibly unclear.