1906 - 1909

The first significant strikes by mail carriers, followed by 300 dismissals.

1910

The first automatic stamp machines are installed for purchase of a 10 centimes stamp.

1912

The first official transportation of mail by air from Nancy to Lunville  is undertaken by lieutenant Nicaud.

1914 - 1918

Because so few men are available, the position of mail carrier is officially opened to women, although women have been performing this service since the second Empire.

1918

Postal checks are created.

1924

The first machines for stamping mail are put into service.

1925

According to the law of 17 July 1925, the Post and Telegraph administration officially becomes the Post, Telegraph, and Telephone administration.  The acronym PTT is officially adopted.

1926

Car service to the countryside is begun: the rural automobile post (P.A.R. in French).

1927 - 1931

The epic period of air mail service (Aéropostale): Daurat, Mermoz, Guillaumet, Saint-Exupéry, and others.

1935

A postal aviation company called Air Bleu is created to service the interior of the country.