AppStream 2.0 User Pool
When you create a new user in the AppStream 2.0 user pool, or assign a user pool user to an AppStream 2.0 stack, AppStream 2.0 sends email to users on your behalf. Users enter the URL that was provided to them in the welcome email, enter their credentials, and then choose Connect.
For more information, see Amazon AppStream 2.0 User Pools.