I've spent much of two days now trying to recover from a Kmail collapse which resulted in it becoming unusable. In the end I created a new Leap 15.1 account, recovered all my emails and other files (Documents, etc.) from backups, and deleted the old Leap account.

I then renamed the new Leap account to the old userid and renamed it's top-level directory, which is supported by Yast. The environment variables (e.g. HOME) are correct, and there's no mention of the old directory name anywhere in /etc,

However I have two remaining problems. The main one occurs when creating a new outgoing email: Kmail complains that the 'sent' mailbox is not defined, but I can't see anywhere to do so.

The other issue is that the change of top-level directory hasn't been picked up by Dolphin, so it complains that the "Home", "Desktop", and "Downloads" directories do not exist. Is there any straightforward way of fixing this? I found it does occur in various files in:
~/,config
~/.pki
~/.local

Any help would be really appreciated.

David L.