Nethserver and Windows Server 2019 Pre 2000 account limitations

NethServer Version: 7.7
Module: Email

I have fully setup nethserver version bound to existing windows AD. I intend to use it as an email server but i have hit a brick wall.

My usernames are in the formart ""
So i have an email account longer than 20 characters which is The user name gets truncated when it synchronised from windows AD. Is there a way of not using the windows pre 2000 to synchronise these accounts and instead sync using the principal name which has more character support. Please help!!!

Hi, Harold. Do you still need help with this?

also interested in me, thanks !!!

As Harold points out it appears to be caused by use of SAMAccountName vs UserPrincipalName.
Some background info: