jenkins 发送邮件失败

javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;
nested exception is:
java.net.ConnectException: Connection refused: connect

at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1934)

at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:638)

at javax.mail.Service.connect(Service.java:295)

at javax.mail.Service.connect(Service.java:176)

at javax.mail.Service.connect(Service.java:125)

at javax.mail.Transport.send0(Transport.java:194)

at javax.mail.Transport.send(Transport.java:124)

at hudson.tasks.Mailer$DescriptorImpl.doSendTestMail(Mailer.java:581)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:497)

at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:335)

at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:175)

后来设置邮件账户如下，可以发送邮件成功