I have some builds that hang when the perforce user is "build". In perforce build has a valid email. In Active Directory there is no email for the build user. I'm fixing this to get around the issue, so I may not be able to reproduce this for long(I'm not the IT guy). I don't know why perforce is trying to get the email from AD, so that may be a perforce plugin bug. Here is the stack trace from the jenkins.err log. The build hangs when trying to send email, you can try to cancel the job, but the job never goes away. Eventually the job does time out, but it can take over 8 hours(4 domains to search through)

javax.naming.NamingException: [LDAP: error code 1 - 00000000: LdapErr: DSID-0C090627, comment: In order to perform this operation a successful bind must be completed on the connection., data 0, vece ]; remaining name 'DC=company,DC=com'
at com.sun.jndi.ldap.LdapCtx.mapErrorCode(Unknown Source)
at com.sun.jndi.ldap.LdapCtx.processReturnCode(Unknown Source)
at com.sun.jndi.ldap.LdapCtx.processReturnCode(Unknown Source)
at com.sun.jndi.ldap.LdapCtx.searchAux(Unknown Source)
at com.sun.jndi.ldap.LdapCtx.c_search(Unknown Source)
at com.sun.jndi.ldap.LdapCtx.c_search(Unknown Source)
at com.sun.jndi.toolkit.ctx.ComponentDirContext.p_search(Unknown Source)
at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.search(Unknown Source)
at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.search(Unknown Source)
at hudson.plugins.active_directory.LDAPSearchBuilder.search(LDAPSearchBuilder.java:52)
at hudson.plugins.active_directory.LDAPSearchBuilder.searchOne(LDAPSearchBuilder.java:42)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:191)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:130)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:95)
at hudson.plugins.active_directory.AbstractActiveDirectoryAuthenticationProvider.loadUserByUsername(AbstractActiveDirectoryAuthenticationProvider.java:27)
at hudson.plugins.active_directory.ActiveDirectoryMailAddressResolverImpl.findMailAddressFor(ActiveDirectoryMailAddressResolverImpl.java:31)
at hudson.tasks.MailAddressResolver.resolve(MailAddressResolver.java:100)
at hudson.tasks.Mailer$UserProperty.getAddress(Mailer.java:514)
at hudson.plugins.emailext.ExtendedEmailPublisher.createMail(ExtendedEmailPublisher.java:335)
at hudson.plugins.emailext.ExtendedEmailPublisher.sendMail(ExtendedEmailPublisher.java:255)
at hudson.plugins.emailext.ExtendedEmailPublisher._perform(ExtendedEmailPublisher.java:247)
at hudson.plugins.emailext.ExtendedEmailPublisher.perform(ExtendedEmailPublisher.java:207)
at hudson.tasks.BuildStepMonitor$3.perform(BuildStepMonitor.java:36)
at hudson.model.AbstractBuild$AbstractRunner.perform(AbstractBuild.java:703)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:678)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:656)
at hudson.model.Build$RunnerImpl.cleanUp(Build.java:171)
at hudson.model.Run.run(Run.java:1454)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:238)