Store and forward for IQ packets?

Can IQ packets be sent toward an offline client but held at the server?

Is this permitted by the protocol?

Reading the RFCs hasn’‘t made this clear to me but i have an application that needs to send IQ-style packets, but the receiving client may not always be there. I’'d rather the packets were delivered when the client reappears, rather than forcing the sender to constantly test, queue and retry…