I need to be able to restrict certain users so that they can only send email to external accounts. If they try to send an email to a local user, it would bound, i.e. joe@domain.com can not send email to bill@domain.com, but can send to any other domain like gmail, yahoo, etc. And they should obviously be able to receive emails from other domains. I have not been able to figure out a way to do this without creating a loop. Wondering if anyone had any suggestions?