電子郵件的普及使用，已成為E化不可或缺的溝通管道。然而，藉由網路的低成本及無遠弗屆，卻被有心人士利用來散發數不盡的廣告信。近年來，由於廣告信的遽增，許多學者紛紛提出郵件過濾之研究。在IT產業中，也逐漸發展出不同解決方案的垃圾郵件過濾系統。
    在過濾系統中，郵件處理量必然會影響速度。當處理量大時，郵件過濾系統將會成效不彰，並失去其郵件的時效性。在目前各個過濾系統中，針對單一郵件網域的超高負載情況，尚無解決之道。
    本研究目的，將以分散式架構來規劃垃圾郵件過濾系統，並取其以往系統之優點，改良缺點而加以實作，解決現有垃圾郵件過濾系統在超高負載時的瓶頸。然而，透由網頁介面，提供使用者回饋機制，並將所誤判之郵件加以修正及學習，減少再次誤判的機會。

To use E-mail is an indispensable for the way of communication in the E-generation. However, someone make capital of it to send countless advertisement letters by the advantage of network that has low cost and endless scope. Due to advertisement letters violently increase, a lot of scholars bring up the investigations into mails of percolation in the several years. People progressively develop various solutions of SPAM mail filter system.

When handle a large number of mails that can effect the speed inevitably. SPAM mail filter system will inefficiency and that can loss the mails timeliness when the system deal with a great quantity of mails. There are no way of solutions aim at an overload situation by single mail domain in every SPAM mail filter system presently.

The purpose of this study, we use distributed architecture to design the spam mail filter system. We take some advantage and ameliorate  some drawback from old system to construct IM-SPAM system. According to experimental result, the IM-SPAM system solved the bottleneck in system is overloaded. Although we also provided a web-based interface for administrative and user can do the system configuration and set up their filtering policies and feed back spam mail information. This system will analyse feedback information and mistrial fixed. That will reduce wrong decision again.

IV
中文摘要............................................. I
英文摘要............................................ II
目錄............................................... IV
圖目錄..............................................VII
表目錄.............................................. IX
1. 緒論............................................ 1
1.1. 研究背景..................................... 1
1.2. 研究動機..................................... 1
1.3. 研究目的..................................... 2
1.4. 論文架構..................................... 2
2. 相關研究......................................... 4
2.1. 郵件防堵技術分析： ............................ 4
2.1.1. 黑名單分享(RBL) .......................... 4
2.1.2. 貝氏過濾法（Bayesian Filtering） .......... 4
2.1.3. 貝氏過濾搭配啟發式過濾.................... 5
2.1.4. SPF(Sender Policy Framework) .............. 5
2.1.5. DNS 反查................................. 6
3. 系統架構......................................... 7
V
3.1. IM-SPAM 組成元件.............................. 8
3.1.1. DNS System ............................... 8
3.1.2. Database System .......................... 8
3.1.3. Core System.............................. 9
3.1.4. Analysis/Report System.................... 9
3.2. Core System 架構.............................. 9
3.3. Alalysis/Report System ....................... 13
3.4. IM-SPAM 運作模式............................. 13
4. 系統實作........................................ 17
4.1. IM-SPAM Gateway 開發平台與工具................ 18
4.2. IM-SPAM Gateway 規劃圖........................ 19
4.3. Database System .............................. 19
4.4. DNS System................................... 21
4.5. Core System.................................. 24
4.6. Analysis/Report System ....................... 28
4.7. IM-SPAM Gateway 運作流程...................... 32
5. 系統安裝與實測.................................. 35
6. 結論與未來方向.................................. 39
6.1. 結論與貢獻................................... 39
VI
6.2. 未來方向.................................... 39
參考文獻............................................ 40
附錄1............................................... 44

圖目錄
圖3-1. 組成IM-SPAM 的四大系統元件...................... 8
圖3-2. IM-SPAM Gateway 運作模式....................... 16
圖4-1. IM-SPAM 內系統元件及子元件..................... 17
圖 4-2. 分散式IM-SPAM Gateway 架構圖.................. 19
圖 4-3. Master Database Config 檔...................... 20
圖 4-4.Slave Database Config 檔....................... 21
圖 4-5. /etc/named.conf 設定檔中ACL 與VIEW 的設定....... 22
圖 4-6. ./spam/im.tku.edu.tw 設定檔................... 23
圖4-7. ./external/im.tku.edu.tw 設定檔................ 23
圖4-8. 透由ACL 及VIEW 設定後，DNS 運作方式............. 24
圖 4-9. Analysis/Report System 運作流程................ 29
圖4-10. 使用者郵件攔截清單........................... 32
圖4-11 IM-SPAM 整體運作流程........................... 33
圖5-1. IM-SPAM 實測時，CPU 一天的負載圖................ 37
圖 5-2. 經過IM-SPAM 郵件過濾後的Mail Header 資訊....... 37
圖 5-3. 使用者完整郵件清單(包含正常郵件與垃圾郵件) ..... 38

表目錄
表 5-1. 95/5/1~95/5/10 總信件、垃圾郵件及正常郵件數量.. 36

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