Add User Principal Name Suffixes

You can use Active Directory Domains and Trusts to add user principal name (UPN) suffixes for the existing user account. The default UPN suffix for a user account is the Domain Name System (DNS) domain name of the domain that contains the user account. You can add alternative UPN suffixes to simplify administration and user logon processes by providing a single UPN suffix for all users. The UPN suffix is used only within the Active Directory forest, and it is not required to be a valid DNS domain name.

Membership in Domain Admins or Enterprise Admins , or equivalent, is the minimum required to complete this procedure. Review details about using the appropriate accounts and group memberships at http://go.microsoft.com/fwlink/?LinkId=83477.

To add UPN suffixes

1. Open Active Directory Domains and Trusts. To open Active Directory Domains and Trusts, click Start , click Administrative Tools , and then click Active Directory Domains and Trusts .
2. In the console tree, right-click Active Directory Domains and Trusts , and then click Properties .
3. On the UPN Suffixes tab, type an alternative UPN suffix for the forest, and then click Add .
4. Repeat step 3 to add additional alternative UPN suffixes.