linux怎么发送外部邮件,集群linux如何发送邮件

最近有个邮件发送的需求，实现很简单，网上一搜一大片关于邮件发送的demo
然后一通的抄写，测试。。。邮件收到，通过。（Windows10）

代码写的太嗨了。。。

打包上传到阿里云服务器（centos）运行，结果就抛出异常

Caused by: com.sun.mail.util.MailConnectException: Couldn't connect to host, port: smtp.mxhichina.com, 25; timeout -1at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2209)at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:740)at javax.mail.Service.connect(Service.java:366)at org.springframework.mail.javamail.JavaMailSenderImpl.connectTransport(JavaMailSenderImpl.java:517)at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:436)... 13 common frames omittedCaused by: java.net.ConnectException: Connection timed out (Connection timed out)at java.net.PlainSocketImpl.socketConnect(Native Method)at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)at java.net.Socket.connect(Socket.java:589)at java.net.Socket.connect(Socket.java:538)at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:359)at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:238)at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2175)... 17 common frames omitted

奇怪了。。。这是什么鬼。。。

搜下好多人都碰到了和我一样的问题。。。。。
随机点开一个参考

https://segmentfault.com/q/1010000011527563

javax.net.ssl.SSLSocketFactory465465

打包上传测试，通过

完美