Hi all, I run an Exchange 2000 server using Panda Antivirus and have applied all of the latest patches to the machine. All of my network machines also have Panda and the latest virus definitions and Windows patches. My server catches SoBig on a regular basis (last count over 2800 incidences). Lately I've been receiving automated notifications from other organizations that my mail is undeliverable due to the SoBig virus. These are emails that I'm not even sending, and I understand that this is the way SoBig operates, however I'm not sure how I could be sending these emails given the scenario I first described (updates and antivirus on all machines). I've even tried running a SoBig.F removal tool and have found nothing on any of my machines. Anyone have some advice?