The Royal Mail states - "Airmail delivery aims for Europe are 3-4 working days and 5-7 working days for the rest of the world. These aims include items being sent by the Airsure service. Delivery targets are not guaranteed and we do not accept any claims for the delay of an item. A delivery aim refers to the point of delivery, not the point of transfer from one country to another".
I posted an item to the Costa Del Sol, Spain on 1/7/08 it is now the 26th it has still not arrived. Their advertising regarding priority handling abroad is at the very least misleading as they have no control whatsoever when the item leaves the uk.