Designing And Programming Cross-platform Mail User Agent

Email takes on an ever greater role in personal and business communication. Mail User Agent (MUA) is a client program that allows one to send and receive email. Currently widely used MUA developed for specific platform, for example Outlook Express is MUA that developed for the Windows platform, Kmail is MUA that developed for the Linux platform. The paper develops cross-platform MUA.Via adopt Kylix3 and Delphi7, rapid application development tools, write the application using CLX(component library for cross-platform) technology and self-ordained cross-platform class libraries, complete cross-platform MUA. By writing program just this once, program can run on Windows platform and Linux platform, this development solution increases developer productivity and speed. It is advantage for this development solution.I put forward the generic principles of programming cross-platform code, use conditional compilation order to assert cross-platform application, deal with the difference between Windows and Linux in program source code, complete cross-platform source code, compile source code using Delphi7, then the compiled application runs on Windows. Compile source code using Kylix3, then the compiled application runs on Linux.Firstly the paper introduces MUA, then talks about Internet email system, next introduces technical implementing of cross-platform MUA, including development tools, writing cross-platform program, Object-Oriented design, Object-Oriented program, GUI design and implement, configuration file formats, mailbox formats, implement function, analyzing technical difficulty and key technology, advanced characteristic. Finally the paper looks into the future of MUA and foreground of developing cross-platform applications, moreover, Point out some work to do in the near future.