ABL: An original active blacklist based on a modification of the SMTP

Pablo M. Oliveira; Mateus B. Vieira; Isaac C. Ferreira; João P. R. R. Leite; Edvard M. Oliveira; Bruno T. Kuehne; Edmilson M. Moreira; Otávio A. S. Carpinteiro

arXiv · 2208.10602

ABL: An original active blacklist based on a modification of the SMTP

Pablo M. Oliveira·Mateus B. Vieira·Isaac C. Ferreira·João P. R. R. Leite·Edvard M. Oliveira·Bruno T. Kuehne·Edmilson M. Moreira·Otávio A. S. Carpinteiro

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Abstract

This paper presents a novel Active Blacklist (ABL) based on a modification of the Simple Mail Transfer Protocol (SMTP). ABL was implemented in the Mail Transfer Agent (MTA) Postfix of the e-mail server Zimbra and assessed exhaustively in a series of experiments. The modified server Zimbra showed computational performance and costs similar to those of the original server Zimbra when receiving legitimate e-mails. When receiving spam, however, it showed better computing performance and costs than the original Zimbra. Moreover, there was a considerable computational cost on the spammer's server when it sent spam e-mails. ABL was assessed at the Federal University of Itajub\'{a}, Brazil, during a period of sixty-one days. It was responsible for rejecting a percentage of 20.94% of the spam e-mails received by the university during this period. After this period, it was deployed and remained in use, from July-2015 to July-2019, at the university. ABL is part of the new Open Machine-Learning-Based Anti-Spam (Open-MaLBAS). Both ABL and Open-MaLBAS are freely available on GitHub.

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Pablo M. Oliveira, Mateus B. Vieira, Isaac C. Ferreira, João P. R. R. Leite, Edvard M. Oliveira, Bruno T. Kuehne, Edmilson M. Moreira, Otávio A. S. Carpinteiro. 2022-08-22. ABL: An original active blacklist based on a modification of the SMTP. https://arxiv.org/abs/2208.10602

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