Resolved it myself. I came across the Wiki page http://wiki.jboss.org/wiki/Wiki.jsp?page=ConfigUIL2 where it said in the section "JMS client properties for the UIL2 transport": anonymous wrote : org.jboss.mq.il.uil2.serverAddr: This system property allows a client to override the address to which it attempts to connect to. This is useful for networks where NAT is ocurring between the client and JMS server. So adding following to my JNLP file fixed it:<property name="org.jboss.mq.il.uil2.serverAddr" value="mail.fpc.be"/> View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4043942#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...