I use fastmail to host my own domain. I alias all users to myself. Any email I get to aliases that don't end in e.g. ".s" automatically goes to a filtered fol

I use fastmail to host my own domain. I alias all users to myself. Any email I get to aliases that don't end in e.g. ".s" automatically goes to a filtered folder. So blah.s@example.com goes to my inbox, blah@example.com gets filtered. $5/month is cheap. I only use one domain, but presumably you could even host multiple domains using a similar setup.