Not sure if this is a virus or not but something weird happened today. I have a POP server running on W2003. I emailed a friend from a valid account on my domain and asked them to send an email to a fictitious mailbox on my domain (which I just made up from random letters). Because the mailbox doesn't exist it went into a catch all account. About 30 minutes later I caught some SPAM in the same catchall account that was addressed to the same fictitious email I address that I asked my friend to email. Coincidence? I think not. So there must be a virus on either my server or my friend's PC that was able to get the email address and send a SPAM email back to me.
Does anyone have an idea what this could be and on which end it would reside?
Many thanks.