Java Socket邮件发送程序SMTP客户端邮件发送程序的实现原理非常简单，首先建立和邮件服务器的Socket连接，然后和服务器握手，发送各个SMTP指令，并按照邮件格式封装邮件体内容，最后发送即可。-Java Socket client mail program SMTP mail program implementation principle is very simple, first create the Socket connection and mail server, and