I wonder makes them send me that email. As in what were they doing I wonder.
They were just reviewing your shipment to make sure it's legal to be put on a plane and flown internationally. Certain items (certain Li-ion batteries for example) are ground transport only and can't be flown.. so they're just checking for any of those kinds of restricted items. I've had dozens of shipments reviewed by GSP. Many times the item in question actually wasn't permissible for international air transport but eBay puts in on the plane anyway after their little review (where I'm pretty sure they just hold onto your shipment for a few hours before putting it back in the mail stream).