Exchange 2007 Spamming
Posted on 2007-10-18
We are having major problems sending email from our Exchange 2007 Server. Our server is appearing on blacklists and our outbound email is being refused. Upon inspection of the Outbound SMTP Queue, I have found literally hundreds of outbound emails, all have "From: <>" and "To:" random email domains. Its clear to me that something is using our Exchange server to send spam, most likely an internal MAPI client, however I am unsure/unable to locate the source of the problem.
Our setup is Exchange 2007 server which also is running Trendmicro Scanmail 8. The exchange server is behind a firewall and has a public IP nat'd to it on port 25. All outbound port 25 traffic is blocked expect from the Exchange IP.
This is a major problem and is effecting our business, therefore I am awarding 500 points to whoever can help me resolve this issue quickly...