本程序实现对SMTP（简单的邮件传输协议）数据包的捕获和重组，还原。基于base64编码与解码，利用libnids网络数据捕获包工具捕获原始的邮件信息。-The program realization of the SMTP (Simple Mail Transfer Protocol) packet capture and re-restore. Base64 encoding and decoding based on the use libnids network data capture