I have an employee which is using Outlook 2007 in cache mode. They connect to the exchange server using HTTPS over RPC. The exchange server in 2007. They had emails that would not go out of their outbox. I told them to close Outlook and reboot their computer and then open outlook again and see if the email were sent. They did this. The emails were gone from the outbox but did not show up in the sent item box either. When I checked message tracking on the server. They were not there either. Has anyone ever seen this before? Does anyone know what happened and how to prevent this.