报错信息：Request processing failed; nested exception is org.springframework.mail.MailSendException: Mail server connection failed; nested exception is javax.mail.MessagingException: Could not connect to SMTP host: smtp.qq.com, port: 465;
往下看，找到根本原因：
javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
在网上找了半天没找到解决方法，后来在Stack Overflow上找到了答案。
原来是jre版本大于1.8.0_181之后在 jre/lib/security/下的java.security文件中有这样几行代码
注释掉前两行，重启服务器，即可解决拒绝安全连接问题
记得esc :wq
成功！
这里附上stack overflow的原文链接：java - SSLHandShakeException No Appropriate Protocol - Stack Overflowhttps://stackoverflow.com/questions/38205947/sslhandshakeexception-no-appropriate-protocol
