I removed the two files ~/.local/share/akonadi/db_data/ib_logfile0 and ~/.local/share/akonadi/db_data/ib_logfile1
Now Akonadi starts. And it seems no mails are lost
I removed the two files share/akonadi/ db_data/ ib_logfile0 share/akonadi/ db_data/ ib_logfile1
~/.local/
and ~/.local/
Now Akonadi starts. And it seems no mails are lost