I'll go straight to the issue I got recently.
I got an IBM server that running MS Windows Server 2003 SE, it basically works as: domain controller, offline e-mail(MS Exchange), and file server.
Lately, as I checked my MS Exchange server, there're some emails were sent from my Exchange server(sender is firstname.lastname@example.org
) to some unknown domains(etc: abc.com, gzit.net....), it seem like my server sending SPAM. I've used relay filter to get rid of it but not completely fix it.
Can someone tell me what is the reason and how can I absolutely fix it? (Is it cause by virus or someone use my server to send SPAM?)