well, just looked in messages.log, each time I created a user I got a quite clear error stating
[ERROR] failed to modify UPN suffixes
I also found this
still, It was an out of the box installation.
I think we found the problem, now for the solution? 
well, just looked in messages.log, each time I created a user I got a quite clear error stating
[ERROR] failed to modify UPN suffixes
I also found this
still, It was an out of the box installation.
I think we found the problem, now for the solution? 