anonymous wrote : I put into the JBOSS_HOME/server/default/lib 2 jars mail.jar and activation.jar, but I still get this error Placing the mail.jar in the server/default/lib should have worked. Can you run this command and post the output: jar -tf mail.jar This will display the contents of the mail.jar. Just wanted to make sure that this jar file has no problems. I tried out that sample code you had posted(with a few minor changes) and it worked fine, both in jboss and as a standalone program. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3957972#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...