Our post-build email notification appears to be hanging while retrieving a user's email address through active directory.
Additional info:

• On the job page's build history, the build will show as complete, with no [x] button.
• The console output of the build will have a spinning circle indicating it is still working.
• On the executor list, the build still shows as running, but the [x] button does not have any effect

thread callstack:

at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:152)
at java.net.SocketInputStream.read(SocketInputStream.java:122)
at sun.security.ssl.InputRecord.readFully(InputRecord.java:442)
at sun.security.ssl.InputRecord.read(InputRecord.java:480)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:927)

• locked java.lang.Object@6edd1ae2
  at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1312)
• locked java.lang.Object@7610244a
  at sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:702)
  at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:122)
• locked sun.security.ssl.AppOutputStream@52ce8b8d
  at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
  at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
• locked java.io.BufferedOutputStream@3d45174a
  at com.sun.jndi.ldap.Connection.writeRequest(Connection.java:431)
• locked com.sun.jndi.ldap.Connection@74c20900
  at com.sun.jndi.ldap.Connection.writeRequest(Connection.java:404)
  at com.sun.jndi.ldap.LdapClient.extendedOp(LdapClient.java:1200)
  at com.sun.jndi.ldap.LdapCtx.extendedOperation(LdapCtx.java:3206)
  at hudson.plugins.active_directory.ActiveDirectorySecurityRealm$DescriptorImpl.bind(ActiveDirectorySecurityRealm.java:486)
  at hudson.plugins.active_directory.ActiveDirectorySecurityRealm$DescriptorImpl.bind(ActiveDirectorySecurityRealm.java:430)
  at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:273)
  at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:219)
  at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:163)
  at hudson.plugins.active_directory.AbstractActiveDirectoryAuthenticationProvider.loadUserByUsername(AbstractActiveDirectoryAuthenticationProvider.java:53)
  at hudson.plugins.active_directory.ActiveDirectoryMailAddressResolverImpl.findMailAddressFor(ActiveDirectoryMailAddressResolverImpl.java:54)
  at hudson.tasks.MailAddressResolver.resolve(MailAddressResolver.java:122)
  at hudson.tasks.Mailer$UserProperty.getAddress(Mailer.java:560)
  at hudson.plugins.emailext.EmailRecipientUtils.getUserConfiguredEmail(EmailRecipientUtils.java:110)
  at hudson.plugins.emailext.plugins.recipients.CulpritsRecipientProvider.addRecipients(CulpritsRecipientProvider.java:41)
  at hudson.plugins.emailext.ExtendedEmailPublisher.createMail(ExtendedEmailPublisher.java:578)
  at hudson.plugins.emailext.ExtendedEmailPublisher.sendMail(ExtendedEmailPublisher.java:306)
  at hudson.plugins.emailext.ExtendedEmailPublisher._perform(ExtendedEmailPublisher.java:297)
  at hudson.plugins.emailext.ExtendedEmailPublisher.perform(ExtendedEmailPublisher.java:244)
  at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:20)
  at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:770)
  at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:734)
  at com.cloudbees.plugins.flow.FlowRun$BuildWithWorkspaceRunnerImpl.cleanUp(FlowRun.java:242)
  at hudson.model.Run.execute(Run.java:1805)
  at hudson.model.Run.run(Run.java:1697)
  at com.cloudbees.plugins.flow.FlowRun.run(FlowRun.java:167)
  at hudson.model.ResourceController.execute(ResourceController.java:89)
  at hudson.model.Executor.run(Executor.java:240)
  at hudson.model.OneOffExecutor.run(OneOffExecutor.java:43)