I must admit I did a lot of things those last nights and its hard to understand what went wrong. Yes, I removed nethserver-mail-server using the UI.
A but later I tried to install Sogo, after what it refused to start anymore, complaining about a segfault that coud be linked to a lock file in /var/run.
Anyway, this particular problem went away, so let’s forget it except if somebody chimes in on this thread.
Thanks