The difference between COM object and object module of .NET framework was elaborated. And the interoperation realization method between COM and .NET while COM as the server and .NET as the client, and con the contrary while .NET as the server and COM as the client was respectively narrated. Calling COM component in unmanaged code (.NET code) and .NET component in managed code was realized by taking advantage of runtime callable wrapper RCW and COM callable wrapper CCW. Thus, in the situation of the .NET technical maturing, programming of using the COM technology will much less than before. But the COM technology would not be completely replaced by .NET in the near future. So a great deal of existent products which are developed using COM component technology are protected and used through realizing the interoperation between the COM and the .NET technology, which also makes the COM programmers use easily the software based on the .NET technology.

Along with wide application of e-mail nowadays, a large number of spam flood into people’s life and bring catastrophe to their work and study. Now new spam is changeable which makes traditional and single method for anti-spam powerless. In response to this problem, three popular spam filtering technologies were introduced, which have been implemented on spam filtering field. After analyzing their advantages and disadvantages, The white and black lists technology, Rule-based filtering technology and Bayesian filtering technology to make the best use of the advantage of these algorithms were integrated. Consequently a layered spam filtering system model was set up, and the performance analysis of the system was made.