These stamps were used in the states under French mandate after WWI (among them Syria)
around 1925.
The text is 'DOUANE DES ÉTATS SOUS MANDAT FRANÇAIS'
(Customs of the states under French mandate).
I do not know why there were a blue and a green stamp.
(blue stamp scanned by Christian de Ryck,
green stamp scanned by Pascal Pette)
This is a stamp in use c. 1955 for imported cards.
The text is 'DOUANES DE SYRIE' ('Syrian customs') and an
Arabic inscription.
(scanned by Pascal Pette)