We are running Exchange 2003. A couple of weeks ago, one of our users sent a message to 3 other users. She received a message "The destination server for this recipient could not be found in Domain Name Service (DNS). Please verify the email address and retry. If that fails, contact your administrator." It was only for this particular message. She had previously sent messages to them with no problem, and has since been able to. It was only this one message. The proble is that she is now receiving the same message with the same error muliple times a day, regarding the same original message. Is there anyway to stop this one message from attempting to be delivered. Hope that wasn't to confusing. Thanks.