java.net.SocketException: Connection closed by remote host

	at sun.security.ssl.SSLSocketImpl.checkWrite(Unknown Source)

	at sun.security.ssl.AppOutputStream.write(Unknown Source)

	at com.sun.mail.util.TraceOutputStream.write(TraceOutputStream.java:114)

	at java.io.BufferedOutputStream.flushBuffer(Unknown Source)

	at java.io.BufferedOutputStream.flush(Unknown Source)

	at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:2104)

Caused: javax.mail.MessagingException: Can't send command to SMTP host;
  nested exception is:
	java.net.SocketException: Connection closed by remote host

	at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:2106)

	at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:2093)

	at com.sun.mail.smtp.SMTPTransport.close(SMTPTransport.java:1184)

	at javax.mail.Transport.send0(Transport.java:197)

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

	at hudson.tasks.Mailer$DescriptorImpl.doSendTestMail(Mailer.java:613)

	at java.lang.invoke.MethodHandle.invokeWithArguments(Unknown Source)

	at org.kohsuke.stapler.Function$MethodFunction.invoke(Function.java:396)

	at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:408)

	at org.kohsuke.stapler.interceptor.RequirePOST$Processor.invoke(RequirePOST.java:77)

	at org.kohsuke.stapler.PreInvokeInterceptedFunction.invoke(PreInvokeInterceptedFunction.java:26)

	at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:212)

	at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:145)

	at org.kohsuke.stapler.MetaClass$11.doDispatch(MetaClass.java:535)

	at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:58)

	at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:747)

	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:878)

	at org.kohsuke.stapler.MetaClass$4.doDispatch(MetaClass.java:280)

	at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:58)

	at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:747)

	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:878)

	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:676)

	at org.kohsuke.stapler.Stapler.service(Stapler.java:238)

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)

	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:873)

	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1623)

	at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:154)

	at hudson.plugins.locale.LocaleFilter.doFilter(LocaleFilter.java:42)

	at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:151)

	at jenkins.telemetry.impl.UserLanguages$AcceptLanguageFilter.doFilter(UserLanguages.java:128)

	at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:151)

	at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:157)

	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)

	at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:99)

	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)

	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)

	at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:90)

	at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:171)

	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)

	at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:49)

	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)

	at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:82)

	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)

	at org.kohsuke.stapler.DiagnosticThreadNameFilter.doFilter(DiagnosticThreadNameFilter.java:30)

	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)

	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:540)

	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)

	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)

	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)

	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)

	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1700)

	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)

	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1345)

	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)

	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:480)

	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1667)

	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)

	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1247)

	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)

	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)

	at org.eclipse.jetty.server.Server.handle(Server.java:505)

	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:370)

	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:267)

	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)

	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)

	at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117)

	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)

	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)

	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)

	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126)

	at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366)

	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:698)

	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:804)

	at java.lang.Thread.run(Unknown Source)