[jacalata]

Yea, but that's if you want to emulate iMessage to the Apple servers in order to send actual iMessages. I think the OP was asking about emulating it to the airplane firewall in order to tunnel through, which could be a lot easier and more useful.

[evan_]

It's unlikely that they're inspecting the packets at a level deep enough to tell what they actually are. More likely that they're just letting you access certain servers for $2.