Here's a partial explanation: The reason you get an exception is that your smtp server rejects the connection as there is no from address in the email (this is 550 administrative error bit). Fortunately my smtp server doesn't :) I can see from the email sent that the return-path is correctly set (to that from mail-service.xml) but not the from address. You say this worked when you did a JNDI lookup for the mail service. Could you post the code you used to send an email where it worked? Thanks View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4010549#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...