I'm not the poster you're replying to, but i did the same thing and use Purelymail (and their web interface, which i think is open-source)

it's a very cheap no-nonsense service, i recommend it

I've been pretty happy on Fastmail as a custom-domain email host the last few years.

I ended up on Zoho because I wanted to be cheap. So far that's worked out well for me.