When you create a domain, Windows offers the name of the root domain and the current domain as the default UPN suffixes. Users can log on with the UPN, such as email@example.com, or with the pre-Windows 2000 logon name, such as username. In some situations you might want to add other UPN suffixes. For example, maybe your logon domain is example.com, but all user e-mail goes to addresses at woodgrovebank.com. To help users remember their UPNs, you decide to add the UPN suffix woodgrovebank.com to the domain. You can do just that with the Active Directory Domains And Trusts Console.Open the console, click the Active Directory Domains And Trusts branch, and choose Action, then Properties to open the UPN Suffixes tab. Click in the Alternative UPN Suffixes box and type the suffix to add (such as woodgrovebank.com) and click Add. Repeat the process to add other UPN suffixes to the forest.