When trying to send a message to a recipient, the sender is receiving an immediate bounceback message.
A policy set by your administrator may be causing this error to occue. Policies may be set that certain types of information cannot leave the organization's email system and/or network. Please note these attempts are logged and monitored.
Delivery Status Notification (Failure) email message
The user may consult with their administrator to see the exact reason why the message was denied delivery.