Using a profiler and driving up the load I was unable to reproduce the out of memory situation. It seems to recover all the memory when the sessions die down. I have a new theory, I think my async timer driven thread is either getting locked up, or dying, or something, letting the inbox backup until it's too full and is unrecoverable. Trying to process a 800 MB inbox then leads to the out of memory situation. Not sure if there's a bug/issue with the timer/async stuff, or something else. I'll report back if I can track it down. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4101126#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...