I have one user (Windows 7, Outlook 2010 and MS Exchange Server) that is having random issues with email. She types and sends messages via Outlook 2010. Everything seems 'normal'. But, she later learns that the recipient didn't receive the message. Furtehr, the message is not in the Sent folder (as are all other items) and is not stuck in the Outbox. Its as if the message was never created. Also, not in 'Draft as the user clicked 'send'. User is also set for cache mode and store is local.
All other users on the network are ok, not seeing this issue at all. I have already had someone remove and reinstall Office 2010 and the SPs. Still happens.