1.java mail实现Email的发送,完整代码：https://blog.csdn.net/qq_37272886/article/details/78655418
2.java后台代码发送邮件：https://www.cnblogs.com/xuyou551/p/8126279.html
3.简单实现邮件发送代码：https://www.jb51.net/article/107575.htm
4.http://www.runoob.com/java/java-sending-email.html