Sending Items, while offline

Hi,
i wanted to ask if its possible, to send an item, then the seller is offline.

To go more into detail:
I would like to send an item, to a person (assuming i know his/her UUID/Ingame Name) after a certain event was trigged on a website.

Just a simple example:
Person a clicks on an object ingame, opel url request comes. User confirms. He comes to a webpage (i.e. a shop) and has serval items to choose. He clicks on one item he likes and confirms it. Now i'd like that this item is sent to this player (similar to the function of SLexchange).

Anyone can help me with this (with a little piece of code for example) or at least give me some ideas of how it could be realized. How does SLexchange handle it?

Thanks in advance,
Lafiel

[I only understand this at a high level. It's unclear, from your post, how much you know about existing delivery systems.]

SLX and OnRez provide scripted boxes to sellers. The seller rezzes the box on her own land, fills the box with her products, and lists the contents on the respective site. When someone purchases an item on the site, a signal is sent to the box in-world and the item gets delivered to the purchaser.

The seller doesn't have to be online (hell, neither does the purchaser) for this to work. The website transmits the recipient's UUID to the seller's box as part of the delivery request.

If you're asking how to implement such a system in detail, well... search me. =)

Guessed something like that. One thing that bugs me about it, is how to contact a ingame "Box" from outside (a Webserver)? Is there a certail url you have to call?