I've just spent 4 months in Kabul.
It was routinely taking 18 days for letters and over a month for parcels (2kg limit). Eblueys were anywhere from a day to a week - depending on the printer working!
The US have a great system - up to 31Kgs per parcel, each way, FREE! It took 7 days for two 20kg boxes to come from Kabul to an American serviceman I work with. The US postal system flys it stuff via contract/commercial and dos not rely upon space available on Mil flights.
At least emails get through quickly....