本程序使用JavaMail进行收取和发送带附件的邮件，使用XStream进行对象和XML之间的转换，并将邮件对应的XML文件和邮件的附件保存到本地的相应目录中-This program uses JavaMail to receive and send messages with attachments, using XStream to convert between objects and XML, and XML files and the corresponding e-mail e-m