[JDEV] delayed messages

[Bill Abbas]

>From the JPG:

"If a message or presence is sent to an offline Jabber entity, the
server stores it. When the entity comes online, the data is deliverd."

Couple of questions:

I've seen this happen in Gabber, but not in my ICQ client.  Does this
deferred delivery apply to packets being routed through transports, as
well?  

How does one control this feature?  I want to programmatically disable
it from the sending side, so that the only people who get certain
time-sensitive messages are ones who are currently online.

Thanks.

Bill