There is no good way to block the message from being sent to internal domains on your server. The only way that I can think of that would allow this is if you setup a content filter on each domain that says if its from there then bounce message. But since content filters only work for inbound messages you cannot just setup the rule on the one domain.
Trouble logging in? Simply enter your email address OR username in order to reset your password.
For faster and more reliable delivery, add email@example.com to your trusted senders list in your email software.