很简单的邮件接收客户端，功能比较少但是能体现函数的应用，适合与初学者观看-very simple client to receive mail, but less functional reflect function application, suitable for beginners and watch

java 下pop3的模拟客户端程序 使用java进行编写 可以进行简单的通信-under simulated client prepared for the use of java can be a simple communication