how to use:
find the following code in offlinemsg\src\java\org\jivesoftware\openfire\plugin\OfflineMsg.java
/*
* add your code here to send offline msg
* recipient.getNode() : receive's id,for example,if receive's jid is "23@localhost", receive's id is "23"
* content: message content
*/
add your code for send offline msg, usually is the queue to send msg