This is highly critical - I can only assume that it is a virus.... I have a client with a SBS 2011 box, running Exchange 2010. Something has begun to fill up C Drive hard drive space slowly but steadily. It is down to 4 GB and already they can no longer receive email. I have stopped the email services hoping that will slow it down for now. It runs Symantec Antivirus client and Symantec Mail Security for Exchange. How can I fix this? I'll even pay for professional to remote in and help me. All help is appreciated.