[Arkanosis]

I'm still using Thunderbird on desktop (personal and professional Linux boxes and professional Windows laptop) and K-9 on smartphone (Android). I'm far from being fully satisfied with either of them, but at least they are better than anything else I've tried to date and more importantly they are slowly improving whereas others I've used (eg. Gmail for the browser and Gmail for Android) are quickly becoming worse (except for the last two updates of Gmail for the browser, I've to admit).

I've some hope in getting a nice setup with notmuch, mu4e or some other power-user oriented MUA at some point (being able to type my emails in Emacs is a real selling point for me), but so far I've been hesitant to lose the ability to read non-plain text emails right in my MUA.

[decasteve]

I was in the same boat. I’ve used Thunderbird since it was first released but eventually found my way to a mu4e setup. I’m happy about the switch because I do so much in emacs already but Thunderbird was perfectly fine for me otherwise.