I'm currently using k-9 Mail in my phone.
I'm currently using k-9 Mail in my phone.
I'll upvote FairEmail - a good solid email client and nice ui too. Well worth the time investment imho.
I'm also on K9, while not the prettiest, it's much better than it was.
If you weren't aware Thunderbird and K9 have teamed up. On the roadmap for this year including updating the message view and a major overhaul of the UI:
The K-9 interface looks outdated, does not conform to the current material design (Android platform) standards. We intend to bring it up-to-date with these as well as fix some workflow issues. https://developer.thunderbird.net/planning/android-roadmap
K9 seems fine to me. However note, if you are using mail services such as Protonmail, it is not supported.
FairMail have *tons* of updates. The dev. is working hard.
I've found the account management on FairMail simpler than K-9 Mail. And it had some features K-9 didn't have then (IIRC). Both of them are great options.
E: formatting
BTW, Mozilla said they are going to make the K-9 app Mozilla Thunderbird for Android.
So the UI might change in the near(?) future.
https://9to5linux.com/mozilla-thunderbird-open-source-email-client-is-coming-to-android-devices
(It's been already a year since, but just know it might change.)