javamail不能发送邮件的问题
用javamail写的程序，本机测试可以发送邮件，放到服务器上面发不了，
本机telnet smtp.163.com 25,成功，
服务器telnet smtp.163.com 25，失败，
有人说是服务器的防火墙问题，有点不明白：
是不是只要telnet smtphost 25失败，就无法发送邮件？要是的话，该怎么办呢？
错误提示：
16:47:43,921 ERROR [STDERR] javax.mail.MessagingException: Could not connect to SMTP host: smtp.163.com, port: 25;
nested exception is:
java.net.ConnectException: Connection refused: connect
16:47:43,921 ERROR [STDERR] at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1282)
16:47:43,921 ERROR [STDERR] at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:370)
16:47:43,921 ERROR [STDERR] at javax.mail.Service.connect(Service.java:297)
16:47:43,921 ERROR [STDERR] at javax.mail.Service.connect(Service.java:156)
16:47:43,921 ERROR [STDERR] at javax.mail.Service.connect(Service.java:105)
16:47:43,921 ERROR [STDERR] at javax.mail.Transport.send0(Transport.java:168)
16:47:43,921 ERROR [STDERR] at javax.mail.Transport.send(Transport.java:98)
16:47:43,921 ERROR [STDERR] at tff.util.SendMail.sendMessage(SendMail.java:63)
16:47:43,921 ERROR [STDERR] at zzl.bean.CompanyOP.SendMailAfterRegister(CompanyOP.java:643)
16:47:43,921 ERROR [STDERR] at zzl.servlet.CompanyNewServlet.doGet(CompanyNewServlet.java:146)
16:47:43,921 ERROR [STDERR] at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
16:47:43,921 ERROR [STDERR] at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
16:47:43,921 ERROR [STDERR] at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
16:47:43,921 ERROR [STDERR] at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
16:47:43,921 ERROR [STDERR] at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
16:47:43,921 ERROR [STDERR] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
16:47:43,921 ERROR [STDERR] at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
16:47:43,921 ERROR [STDERR] at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
16:47:43,921 ERROR [STDERR] at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
16:47:43,921 ERROR [STDERR] at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
16:47:43,921 ERROR [STDERR] at java.lang.Thread.run(Thread.java:595)
16:47:43,921 ERROR [STDERR] Caused by: java.net.ConnectException: Connection refused: connect
16:47:43,921 ERROR [STDERR] at java.net.PlainSocketImpl.socketConnect(Native Method)
16:47:43,921 ERROR [STDERR] at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
16:47:43,921 ERROR [STDERR] at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
16:47:43,921 ERROR [STDERR] at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
16:47:43,921 ERROR [STDERR] at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:364)
16:47:43,921 ERROR [STDERR] at java.net.Socket.connect(Socket.java:507)
16:47:43,921 ERROR [STDERR] at java.net.Socket.connect(Socket.java:457)
16:47:43,921 ERROR [STDERR] at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:232)
16:47:43,921 ERROR [STDERR] at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:189)
16:47:43,921 ERROR [STDERR] at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1250)
16:47:43,921 ERROR [STDERR] ... 29 more
[解决办法]
是的 只要telnet smtphost 25失败，就无法发送邮件
把防火墙关掉试试 如果行就是防火墙的问题 仔细的配置一下防火墙
否则就是别的原因导致你的服务器和要访问的SMTP服务器之间网络不通
