ok, but why this file is of default put on "seam" project, (created with "jboss tool")? This may not generate any misunderstanding? And if i put to true the "java2ParentDelegation" flag, what real difference made to my project? Why the problem is only when I send an email asynchronously? I tried to read http://wiki.jboss.org/wiki/Wiki.jsp?page=ClassLoadingConfiguration but I was not very clear Sorry for my continual requests Thanks in advance View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4125713#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...