Ver 5.8 update, made k9mail useless

1: after the pdate K9mail continuisly complains thar its unable to send messages,
2: why have you removed the option of commom inbox contra an overview of all inboxes ?
3: where is the starred messages ?
4: what happened with lomg ress on a message ?
5: can this upgrade be reverted to the earlier versio 5.6 ?

as i cant send messages the app is now useless

You can still long-press messages. The context menu appears on the top of the screen. That makes it possible to directly select multiple messages that you can edit at the same time.

See How to downgrade to an earlier version?

Are you using POP or IMAP?

What error message are you seeing when it complains about being unable to send?

I am using IMAP

The error message (translated from Danish) “unable to send messages” and a warning triangle on top of the android screen