Sentence:  information was filtered through the counting-houses and warehouses of Antwerp; <WSD>posts</WSD> galloped along the roads of the Low Countries, while dispatches streamed through Calais, and were passed off the merchant galleys arriving in London from the Flanders ports. 
Meaning of the word marked with <WSD> tags:  Someone who travels express along a set route carrying letters and dispatches; a courier. (from 16th c.)