The special situation of Egypt as a nominal province of the Ottoman Empire and the special dispensations allowed to European citizens under the Capitulations meant that six foreign nations were allowed to operate national post offices in Egypt via their consulates. These were initially established in Alexandria and Suez, as the main ports at the time, and where most Europeans lived or conducted business. Later further offices were opened in Cairo and Port Said as their importance grew.
These offices gave nationals of the respective countries the facility to send mail from Egypt to any destination within the foreign country served by its own mail routes. They operated with almost complete autonomy outside the Egyptian postal services and used their own national stamps and their own carriers for the transport of mail to and from Egypt. Incoming mails were delivered to the consulate and had to be collected by the addressee from the premises, while outgoing mail had to be franked with the stamps of the nationality of the shipping line. Mail could be sent from within Egypt to the consular post office by payment of the local Egyptian postage. After the introduction of Egyptian stamps in 1866 this led to some letters bearing stamps of both Egypt and of the country of destination. These fascinating "mixed frankings" are much sought-after and command a good premium.
The foreign consular offices were established and operated as follows: France 1837-1931; Greece 1833-1881; Austria 1837-1874; Russia 1857-1875; Britain 1839-1878; Italy 1863-1884. In most cases the offices did not far outlast the first Universal Postal Union convention signed on 9 October 1874, which allowed postage to be paid in Egyptian stamps from anywhere within Egypt to within UPU signatory countries. Some foreign offices, however, continued to operate for the next decade, and the French Post Office hung on tenaciously up to April 1931.
Egypt, Stamps and Postal History Peter A.S. Smith, 1999
Postal History of Egypt to 1900 Samir A. Fikry, 1996