One of my users received a spam message from his internal exchange server on an SBS 2003 machine. The message apparently orginated from an unknown user from his own domain. (i.e. [email protected] received a spam message from [email protected]) However, [email protected] does not exist and there is no mailbox for him. I checked and there are no open relays. What do I need to do to figure out how this happened and how to stop it? The message did show up in the message tracking center. With the following info:
[email protected]
SMTP:Message Submitted to Advanced Queuing
SMTP:Started Message Submission to Advanced Queue
SMTP:Message submitted to Categorizer
SMTP:Message Categorized and Queued for Routing
SMTP:Message Queued for Local Delivery
SMTP:Message delivered locally to [email protected]
SMTP:Store Driver: Message Delivered Locally to Store to [email protected]