Study On Information Security For Enterrpise Email System

With the development of Internet Technology, Electronic Mail is widely used in the Enterprise. E-mail. Application Security issue has been more and more attention. As we all know, three elements of Information Security: Confidentiality, Integrity, and Availability are that as the basic measure of Enterprise Email Security. This basic principle is being challenged in the world today. Two of the most serious threat: SPAM and SMTP Defect Attack. SPAM: The end user(Mailbox) receive a large number of SPAM. Consequently, E-mail Storage Space is occupied by the coutless SPAM. It’s a very serious waste of resources. SMTP Defect Attack: It’s a malicious attack based on SMTP Defect. It may cause a tremendous negative impact on Enterprise Email Application. Especially, in the aspects of Availability and Confidentiality.We will point out that Email Application Security and Anti-SPAM are related to Enterprise’s Core Values and then we will introduce and explain: 1.How does E-mail work in Enterprise? 2. What’s the purpose of SPAM? 3. How to definite SPAM? 4. What’s the type of SPAM? This paper follows the principle: Problem Finding---Problem Analysis---Problem Solving. Problem Finding: After reading a large number of domestic and foreign document regarding the Information Security, we list the most used Security Solution for Enterprise E-mail Application(GreyList, PTR, and Verification Code) in the world today and analyze the defect of the existing Solution and SMTP. Raise the critical questions: A large number of SPAM Attack, Fake(Spoof) Email, Reverse NDR Attack and Password Stealing Attack. Problem Analysis: Stimulate 4 SPAM attacks we mentioned above and deeply analyze the root cause. Qualitative Analysis, Experimental Analysis, quantitative Analysis are being used on the Problem Analysis. Problem Solving: Provide the Solution based on the analysis. Qualitative Analysis, Experimental Analysis, quantitative Analysis, Comparative analysis are being used on the Problem Analysis. 1. Postponed Technology---Delay response in SMTP and will block E-mail Address Search Attack. 2. Non-forced PTR record---Different with PTR(Black/White Solution), It’s a non-forced PTR record. 3. The Recipient list Comparison---The recipients are listed on Recipient list, will be received. 4. The Security Channel among the Internal E-mail Server--- In the most of case, we use TLS/SSL to build Security Channel between Client and Server. However, we always ignore the Security Channel among the Internal E-mail Server. Experiments and the experimental data: We deploy the Exchange Server and free Email Application and stimulate the 4 attacks, deliver a complete statistical result based on the experiments.1. A large number of E-mail Attack Defense2. Fade E-mail(Spoof) Defense3. Non-existing recipient Attack Defense4. Information Stealing DefenseFinally, we generalize common solutions to apply to similar problems, provider Hierarchical solution of Email System. The defense capability of the Enterprise Email System can be improved via the Integration of multi-level security defense plan. In addition, we will put forward some views and suggestions for the trend of Enterprise E-Mail Security---Cloud Service.