The idea of the postal stamp is people to pre-pay a fee for using such service. There are discussions on the first postal stamp but the dominating one is that it is released in England and Ireland on 1st of May 1840, as a part of the Rowland Hill’s postal reforms.
The name of the first postal stamp is Penny Black, it cost 1 pence.
There are several Christmas stamps that can take the credit for being the first one with Christmas design.
Canada – 1898, known as the “Map”, with “XMAS 1898” words on it. There is a story behind it that can contest its first place.
Austria – 1937 (two series, one with a rose, other with zodiacs)
Brazil – 1939 (one with three kings and a star, other with Southern Cross and a child, third with mother and child)
Hungary - 1941
Here are some ideas for Christmas useful gifts: