The SenderInspector (SI) is admin tool that allows you to STOP outgoing-spam for IIS. A spammer's main weapon is a false identity of the sender. The SI disarms a spammer and allows recipient and admin to see the true sender of SPAM. There is nothing in the SMTP standard that can cause a sending site to send the real sender identity. The SenderInspector is a middleware that corrects this disadvantage and causes a sending site to tell the truth in the envelope sender specification. So SI isn't yet another antispam-filter. It allows you to eliminate the source - not consequences of SPAM. In order to do this SI supports two engines to fight against SPAM: - The signature of a sender. - The mailing log. The signature of a sender is an extra (hidden) header in email messages. SI adds it on the fly. The mailing log is Event Log (in the message-sender format) in a light data base. These engines allow you to track SPAM even if customers can send emails anonymously. You can use any of these engines or both at the same time. Try Demo and assure yourself that SI works perfectly. Install full SI if you want: - to avoid mass mailing of spam from your servers, - and always to know the true address of the email sender.