Step 1. Get your own domain. I bought from porkbun. This was a difficult choice for me, having heard /read cases of domain hijacking by unethical domain sellers. Porkbun had decent reviews. Step2. Follow instructions on protonmail custom domains. Wait for all the greyed out tags to turn green. I was impatient and my domain was marked as spam by Spamhaus. Had to open ticket with them to get off their list step3: enjoy!

additional steps. I moved my dns provider to cloudflare if you wish to go that route.

same here. Proton with own domain!

“Just a hobby, won’t be big” - he really didn’t think it will be one of the most sought after projects.