In the past, if I invited someone to a forum, it would change the email to the username, letting me know that the user existed.
Today, this wasn’t the case and I sent a nice invite to a user including a message of how to join.
The view looks exactly the same if the email address existed, or not.
Becomes this, after I hit send.
Because I’m going to be told if the email address is in use or not, being told before I send the invite would a much better experience.