javamail报错,哪位高手帮忙看看啊?谢谢

Question

忘了,把错误贴上去了,运行后报错:
Exception in thread "main" javax.mail.MessagingException: Exception reading response;
  nested exception is:
java.net.SocketException: Connection reset
at com.sun.mail.smtp.SMTPTransport.readServerResponse(SMTPTransport.java:1407)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1205)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:322)
at javax.mail.Service.connect(Service.java:236)
at javax.mail.Service.connect(Service.java:137)
at com.javamail.MailSender.main(MailSender.java:49)
请高手指点.
若删掉" transport.connect(smtp,"username","password"); ",则没有问题,是不是连接的问题啊,谢谢!