I've had this problem before. You can receive emails ok but can't send. I assume you are on a BES with your company. It sounds like you have plugged your handheld into an improperly setup desktop manager software on your computer and have lost the Enterprise connection with your handheld. You may be able to connect to your email on your computer, plug in the handheld and run the desktop manager again, and re-generate the encryption keys and get it back but you may just have to wait until your IT guy gets back to have him re-activate you on the BES. If there are any IT guys on here they might be able to be of more assistance.