A spam rejection scheme during SMTP sessions based on layer-3 e-mail classification

• Main Authors: Marsono, Muhammad Nadzir, El-Kharashi, Mohamed Watheq, Gebal, Fayez
• Format: Article
• Published: Elsevier Ltd. 2009
• Subjects: TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.utm.my/id/eprint/12846/; http://dx.doi.org/10.1016/j.jnca.2008.03.005
• Institution: Universiti Teknologi Malaysia

This paper proposes a scheme that rejects spam e-mails during their simple mail transfer protocol (SMTP) sessions. This scheme utilizes a layer-3 e-mail classification technique, which allows e-mail classes to be estimated before the end of SMTP sessions at receiving e-mail servers. We analyze the proposed scheme using discrete-time Markov chain analysis under varying e-mail traffic loads and service capacities. This paper also considers the effects of e-mail retransmission and illegal spam relaying by zombie systems on the performance of the proposed scheme. Results from our analysis show that e-mail server loading decreases by using the proposed technique. This allows the reduction in non-spam e-mail queuing delays and loss probability. Our scheme also protects e-mail servers from being overloaded by spam traffic and, if performed collectively over the Internet, it is capable of performing outbound spam control.