I use the entire email address as the username in the portal application that I am developing. I don't use LDAP (yet), but am using the DB login module. It works fine. I would do a bit more research into the problem. Sorry I can't give you any ideas of specifically what may be wrong, but I can offer a data point that email addresses can be used as usernames. Gary. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4067636#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...