Evaluating the use of spam-triggered TCP/IP rate control to protect SMTP servers

This paper examines an approach to spam mitigation that rate limits incoming TCP/IP connections to an SMTP server based on the real-time detection of spam within the SMTP message exchange. Our approach is motivated by a desire to cause increased resource consumption at the spammer end of each SMTP connection, and to avoid the negative impact of false-positives by eventually allowing all emails through.We call the tool MT Proxy.MT Proxys spam analysis and traffic differentiation characteristic are analyzed to evaluate the efficacy of this architectural approach to fighting spam.