When did the US postal service begin using electric cars?

The first known test of an electric vehicle for mail collection was in Buffalo, New York, on July 2, 1899, when Buffalo’s superintendent of city delivery, driven by an electric car promoter in his Columbia automobile, collected mail from 40 boxes in an hour and a half – less than half the time it took with a horse drawn wagon. In December 1899, an electric vehicle was tested in Cleveland, Ohio

The first known contracts for transportation by automobile,were for electric models.

In early 1901 the Post Office Department contracted with the Electric Vehicle Company of New York for the transportation of mail between the Buffalo Post Office and a temporary postal station at the nearby Pan-American Exhibition, which ran from May through October 1901. –Later in 1901, the Department contracted with the Republic Motor Vehicle Company for five electric vehicles, with operators, to collect mail from boxes in Minneapolis and to carry mail between the Post Office and its stations beginning January 1, 1902.