If you have an address that you can still use in Cairo Margaret, check this company ARAMEX :: Total Transportation Solutions :: International Express, Domestic Distribution, Freight and Logistics. They bypass the postal system totally. We use it all the time though not for letters - just packages. Hopefully they'll eventually have offices in other places in Egypt but at the moment they're only in Cairo and Alex.
The big attraction is that they give you a box number in the US and another in the UK so if you want to buy anything online but they don't deliver abroad, you use your Aramex box number. We've had everything from shoes to an electronic keyboard delivered. Prices are reasonable and no-one opens things up and rummages through!