Start Mail from scratch

Hey Guys,

I’m running nextcloud 24.0.1 in a linuxserver docker container. Unfortunately I messed up the mail app by trying to get some old userdata out of it.
Is there a way to start over? So, e.g. I delete all the tables and the folder and it will reinitialize itself? I would rather not go on a wild goosechase, since I want all the data gone anyways I assume this would be the easiest solution.

Thank you in advance
Autchi