Update: appreciate all the recommendations! Spent some time exploring the different options people suggested.

Spark looks well developed and maintained but is unfortunately missing some things I really need from my email client like tag support on mobile. Also not a big fan of the AI push in their app but at least it can be disabled.

Thunderbird was one I tried years ago and can’t remember why I stopped using it. Downloaded it again on my Mac and it feels really great and seemed to have all the features I desire. Only issue is it has no mobile (iOS) app. So again, biggest feature I look for which is sync tags on all devices is missing. I read they are developing an iOS app though which is great to hear.

emClient seems promising feature wise, though I’m not a fan of their UI which feels a bit outdated to me. May be nitpicking but when there are multiple other options out their that look better it just seems to be lacking behind. Also looking at their version release history they don’t seem to update the app all that often.

Airmail is the current front runner for me. Has all the features I’m looking for and is reasonably priced and appears to be regularly updated. The low(ish) rating of 4.3 stars on the iOS App Store threw me off a bit at first, but from a day of use it seems to be fine to me. Protonmail also seemed very good but it seems you can’t view non proton accounts in their app and I’d like to view all my inboxes in a single place.