Enable debugger for a mail session

At times you might need to debug a JavaMail application. One option you can use is turning on the JavaMail debugging feature. With this option, the JavaMail API prints interactions with the mail servers, as well as the properties of the mail session, to the stdout output stream, which is redirected to the SystemOut.log file for the specific application server.

The mail debug feature functions, on a per session basis. To enable the JavaMail debugging feature...

  1. Open the administrative console.

  2. Click Resources>Mail Providers>mail_session>Mail Session>mail session.

  3. Click Debug. Debug is enabled for just that session.

  4. Click Apply or OK.

A sample of the JavaMail debugging output is as follows

DEBUG: not loading system providers in <java.home>/lib
DEBUG  not loading optional custom providers file: /META-INF/javamail.providers
DEBUG: successfully loaded default providers
DEBUG  Tables of loaded providers 
DEBUG: Providers listed by Class Name...
Microsystems, Inc], com.sun.mail.imap.IMAPStore=javax.mail.Provider[STORE,imap,com.sun.mail.imap.IMAPStore,Sun
Microsystems, Inc], com.sun.mail.pop3.POP3Store=javax.mail.Provider[STORE,pop3,com.sun.mail.pop3.POP3Store,Sun
Microsystems, Inc]}
DEBUG:  Providers Listed By Protocol...
{imap=javax.mail.Provider[STORE,imap,com.sun.mail.imap.IMAPStore,Sun Microsystems,
Inc], pop3=javax.mail.Provider[STORE,pop3,com.sun.mail.pop3.POP3Store,Sun
Microsystems, Inc], smtp=javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,Sun
Microsystems, Inc]}
DEBUG: not loading optional address map file: /META-INF/javamail.address.map
*** In SessionFactory.getObjectInstance,
  The default SessionAuthenticator is based on...
   store_user = john_smith
   store_pw = abcdef 
*** In SessionFactory.getObjectInstance, parameters in the new session...
DEBUG: mail.smtp.class property exists and points to com.sun.mail.smtp.SMTPTransport
DEBUG SMTP: useEhlo true, useAuth false
DEBUG: SMTPTransport trying to connect to host "smtp.coldmail.com", port 25    

javax.mail.SendFailedException: Sending failed; 
      nested exception is...
      javax.mail.MessagingException: Unknown SMTP host: smtp.coldmail.com;
       nested exception is
       java.net.UnknownHostException: smtp.coldmail.com
       at javax.mail.Transport.send0(Transport.java:219) 
       at javax.mail.Transport.send(Transport.java:81)
       at ws.mailfvt.SendSaveTestCore.runAll(SendSaveTestCore.java:48)
       at testers.AnyTester.main(AnyTester.java:130)

This sample output illustrates a connection failure to a Simple Mail Transfer Protocol (SMTP) server because a fictitious name, smtp.coldmail.com, is specified as the server name.

The following are tips on how to read the debugging output...