Use the userPrincipalName (email style) for AD users
Hi please use userPrincipalName instead the fuuuu... sAMAccount with 20 letter limit.
Björn Stahlberg commented
I agree. Using the userPrincipalName should be supported for Active Directory authentication. Use of LDAP is not an option as this does not respect group memberships. Use of the userPrincipalName (usually the e-mail address of the user) is standard procedure nowadays for AD authentication and federated services.