Preventing spams

This is something that was tested by one community leader.

Basically, you can invite one user to a customer portal. Let's say that the user received invitation but didn't accept it yet and didn't create an account on the portal.

It seems that agents can still assign invited user to a created request or even tag him/her in the comments section. Even if the user didn't register but just received invitation, he/she will still be notified via e-mail about changes made on the issue or mentions in the comments.

I guess this could be a potential problem if let's say, user doesn't want to accept invitation, or if agent sent an invitation to a wrong e-mail.