:tell <user> <message> - to leave a message for an offline user

[urenzel]

The [message] should be send to the public channel when a specific user appears online. Maybe with the preambel: [user]: [somebody] wants you to know: "[message]"

[joen]

That should already be possible via xmpp. I guess if you write a private message to an offline contact, it will be delivered when he/she connects to the server holding the message. But i am not quite sure ...
http://xmpp.org/extensions/xep-0013.html
http://xmpp.org/extensions/xep-0203.html

[thatgim]

I think this feature is really need. It's simple and straight forward.

Should this message be sent after a user joined the channel or said something?