This normal letter sent form Doha to England in 9 Dec 1956 with Queen Elizabeth II stamp with India currency overprint. This stamp used in Arabian Gulf area from 1951 to 1957.

This Registered letter No. 7615 carrying In Memory of John F. Kennedy stamps that issue in 18 July 1966. The letter sent from Qatar to India in 18 July 1966 and arrived in 26 July 1966.

This Registered letter No.2006 is sent from Qatar to Australia, dated 6 October 1969.
The letter traveled by Saudi Arabian Airlines. Carrying Qatar Apollo 11 Moon Mission stamps that issue in 1969.

Qatar old letters
This some of my collection

This Registered letter No.7177 is sent from Qatar to the United States of America, dated 17 October 1966.
Front: carrying Qatar Scouts stamps (Imperforated) with overprint with the new currency.
Back: Souvenir sheet of Qatar Scouts (Imperforated) with Indian currency and stamp with Indian currency.

History of Post office in Qatar

In 1871 Qatar was under the dominance of Turkish troops in Al Ahsaa area (Area in KSA) so a Turkish castle was built in Doha in 1916, when Qatar under the leadership of Sheikh: Abdullah Ben Jassem Al Thani. Upon the signature of Bahrain and Oman the treaty was signed to be under English troop protection. sending is mail and posting via Bahrain post office , moreover , its letters stamped by Bahraini seal , Qatari letter were recognized only through the address of sender .

With the rapid development of the oil industry there was a need to have the office of British counselor in Doha, his special mail was carried through diplomatic suitcase to be sent to Bahrain then the British deputy of Bahrain to be sent abroad .The firm of post office in Qatar was one of the terms of the English protection treaty of 1916 , so, British deputy opens mail service in the building of British counsel in 1950. While there was no special post stamp of Doha, the special stamp of British counsel was used at that time.

The First post office in Qatar
At the beginning of 1951, the first post office was opened in Doha during the reign of Sheikh Ali Ben Abdullah Al Thani. The Indian English stamps were used at that time the stamps bearing the name of Bahrain were replaced by British stamps used in all countries of British protection.

Misyaseed post office
Misyasaed Industrial City is located at the south of Qatar. It houses oil refineries and a huge port for oil crude exportation worldwide. This office was opened in the first of February 1965 under the supervision English mail.

Dukhan post office
Dukhan city is located in the west of Qatar and is famous for oil wells. This post office was opened on 3rd of January 1960. At first it was a branch of Misyaseed post office. It is the third post office in Qatar after Doha and Misyaseed; on 4th of April 1965 it separated from Dukhan post office.