Sometimes a message cannot be delivered. One reason is because the email address is not valid. In this case, verify that you have the correct address. Other causes can be that the recipient’s mailbox is full or the recipient’s mail system is having problems. If a message is rejected, it bounces back to you with a message stating why it could not be delivered. If you can resolve the problem, try resending the email.
If you continue to have the following problems, contact your administrator: