Hi,
I was on vacation.
Did now all this, what is written down here: https://forum.snapcraft.io/t/how-can-i-use-snap-when-i-dont-use-home-user/3352/20?u=zickzack
My Home folder finally moved. Restarted the Computer twice.
Typing:
robert@robert-desktop:~$ mailspring
cannot create user data directory: /home/robert/snap/mailspring/488: Permission denied
What now?