Nice, problem is that most just want you to click a phishing link rather than write back to them. How can we waste phishing attackers time? Boot up a docker image and have them ransomware that?
Ha, I was just like you, just recently starting to look away from GMail, though mostly because of all the incessant and obtrusive ads.
I am using protonmail now, which has the option for a bunch of aliases that I really like, the web interface works fine though it's missing bells and whistles - I do miss the smart grouping of GMail! - and you get to use custom domains. It also provides encryption and you can even get VPN to go with it. Here's all the options you get per tier: https://protonmail.com/pricing
Still an early user, but so far quite happy with it!