K-9 mail, soon thunderbird for android, has been security audited and it looks very promising
Well, alongside with this, Thunderbird has released 115, dubbed “Supernova” with a revamped, modern (finally!) user interface.
Haven’t tried it yet but I will very soon.
Lots of Add-ons don’t work, yet!
Not surprising. Its a total rewrite for the interface and it will break all the interface elements of previous plugins but despite this, still feels like a proper step forward.
Flathub flatpak, while official still has no 115 release yet (still at 102).
Fedora flapak repo is likewise behind at 102.