Hudson could not send mail on our install of Tomcat 5.5.23 (installed on RHEL 5
from YUM repository). The problem went away when we removed the mail &
activation jars from WEB-INF/lib. The error message was:

javax.mail.NoSuchProviderException: smtp
at javax.mail.Session.getService(Session.java:782)
at javax.mail.Session.getTransport(Session.java:708)
at javax.mail.Session.getTransport(Session.java:651)
at javax.mail.Session.getTransport(Session.java:631)
at javax.mail.Session.getTransport(Session.java:686)
at javax.mail.Transport.send0(Transport.java:166)
at javax.mail.Transport.send(Transport.java:98)
at hudson.tasks.Mailer$DescriptorImpl.doSendTestMail(Mailer.java:360)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:103)
at org.kohsuke.stapler.Function.bindAndinvoke(Function.java:57)
at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:75)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:30)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:440)
at org.kohsuke.stapler.MetaClass$9.doDispatch(MetaClass.java:263)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:30)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:440)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:361)
at org.kohsuke.stapler.Stapler.service(Stapler.java:121)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:53)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:45)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:88)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:210)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:870)
at
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
at
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
at
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:685)
at java.lang.Thread.run(Thread.java:619)