In Messenger, if a user is “offline” then no messages will be delivered. You can look at the transports subproject in SVN. There’‘s a generic gateway project that helps keep “legacy” or foreign users sync with the server. There’'s an example called “LoopbackGateway” that provides a minium effort in order to get a gateway working.
I am able to implement this type solution. In this When a user selects I’m sms while closing his messenger. I send some diffrent type of presence notification to his friends.
Like:
SMS
This is not according to XMPP… So client need some modifcation to hadle this.
and I add a logic in OfflineMessageStrategy to send to message in sms. based on user setting.