Mark message deleted

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App

K-9 Mail

App version

9.0

Where did you get the app from?

F-Droid

Android version

8.1

Device model

No response

Steps to reproduce

1. In an old version of K-9 – and an IMAP mail account –, set the setting, that deleted messages are marked as deleted (but not deleted from the server).
2. ‘Delete’ a message in K-9.
3. The message disappears in K-9.
4. Go to another mail program, e.g. Thunderbird on the desktop: The ‘deleted’ message is marked as deleted, but is still in the inbox.
5. Update to version 9.0.
6. ‘Delete’ a message in K-9.
7. The message disappears in K-9.
8. Go to your other mail program: The ‘deleted’ message is really deleted and cannot be found!
9. Investigating the settings for the mail account shows, that K-9 has lost the setting for marking a message as deleted. The fall-back action is to delete it immediately. This is not good, because it can lead to lost messages!

Expected behavior

1. The setting to mark messages as deleted should stay during updates.
2. If it is deleted, it should fall back to a safe setting and not deleting the message immediately! This can lead to lost messages.

Actual behavior

Updating K-9 to version 9.0 replaces the ‘mark deleted message’ with ‘delete message immediately’.

Logs

Changing the upgrade policy might already be too late for most people, but please reintroduce the ‘mark messages as deleted’ option again.

Start by reproducing the upgrade from an older K-9 Mail version to 9.0 with an IMAP account configured to mark messages as deleted, then inspect the account's message-deletion setting. Done means the setting survives the update or safely falls back without immediately deleting messages; verify the behavior in another mail client such as Thunderbird.