I have a Windows Small Business Server 2003 server with the mail queue filling up and depleting hard disk space on the server. The exchange server logs grow to more than 1GB. I have verified that the server is not an SMTP relay. One thing I noticed is that in the ESM Queues, every Queue shows the sender as "Standardbank.co.za"<email@example.com". How do I prevent this constant mass emailing? I have checked each PC and server on the network for viruses/spyware and confirmed that we are clean. Does this sound like it is malware related?