透通式外寄郵件閘道器之建置與應用

Abstract

垃圾郵件防治是當前重要資安工作之一，然而絕大部分的垃圾郵件防治均是針對內收郵件進行過濾，顯少將外寄郵件納入考量，以致於外寄郵件常造成資安管控的死角。除了郵件過濾外，郵件的備分與監控也漸漸受到重視，尤其是具有敏感資料的單位，對此需求更甚。本文中，我們將提出一種透通式的外寄郵件間道器之建置方案，在該閘道器上不僅可以套用現有的垃圾郵件防治技術，以便對外寄郵件進行過濾，而且還可以將這些郵件進行備分，便於日後進行稽核與追蹤。整個系統的建置成本非常低廉，只需一到數台伺服器即可完成。而且由於透通式的特性，使得既有的伺服器以及個人電腦完全不必更改設定，在推行上幾乎不會受到習慣改變而產生任何的阻力。因此，本文所提出之方案是一個可行而又值得推廣與應用之建置方案。

Today, anti-spam is the most important topic of information security. But, most of the anti-spam only filter with incoming mails. Therefore, the outgoing mails become the death corner of information security controlling. Moreover, backup and monitoring for the mails also are the important topics. In this paper, an implement strategy for transparent outgoing mails gateway is proposed. Our proposed mechanism could not only backup the mails, but also audit and trace the mails. Besides, the cost of our proposed system is very cheap and only uses one or several servers to implement. Furthermore, owing to the property of transparency, all servers and pc do not change any setup data. Therefore, the proposed mechanism is very practical for the real implementation and application.