Using Multiple User Principal Name Suffixes
When configuring ADFS in your own local the default login of any user authenticating into the environment would be user@domain.local or something of that sort. At many times, especially when working with multiple applications, we would like the user to authenticate using different login credentials such as user@mynewdomain.com. In order to implement this, we can add suffixes that gives us the ability to user a friendly logon name that is not the same as the domain or parent’s domain name.