I’ve got a cheap VPS to act as a relay with a static, more or less trusted IP address. It just forwards incoming mail to my homelab, and outcoming mail to the recipient. The setup can get pretty complex if you haven’t done this before.

Would probably be a lot easier to just deploy addy to a vps and call it a day

Can’t recommend https://addy.io/ enough, I have been selfhosting it for some time now and have not had any complaints