Suggestions full mail app for Android

I use Thunderbird as my main mail client (portable version, stored inside a VeraCrypt volume file, not so much for security as convenience), for several accounts, sorting, searchable archives, tagging, and so on.

Does anyone have an app for Android (tablet) that can handle the following?

  • Several accounts
  • Several identies for one account (K9 can)
  • Archiving mail in folders, not tagging (K9 can neither)

I like K9, though with the OpenPGP app, symmetric encryption fails utterly.
Any hints, ideas or anything of that kind are gratefully listened to.