Hi
You don’t configure LDAP Settings in Email.
In NethServer, you choose between LDAP or AD when setting up your NethServer. You can’t change this easily later on, so decide wisely!
After setting up an account provider (LDAP or AD) any users or groups you create are actually created in the lDAP (or AD).
You can use the PHPLDAPadmin Plugin by Stephdl to administrate your AD or LDAP, like add in additional attributes.
https://wiki.nethserver.org/doku.php?id=phpldapadmin
EMail settings go automatically to LDAP / AD, depending on what you set in Email on your NethServer.
Hope this helps.
My 2 cents
Andy