Three old town houses on the main square form the basis of what is today the post office. Numbers 7 to 9 have been official buildings, or the residences of well-known individuals, since the 18th century.

In 1902 the three houses were combined by master cathedral builder Matthäus Schlager into one art nouveau building. This became the seat of the district authority.

In 1950, the building was radically modernised and converted into the post office. The colourful designs by Ried painter and graphic artist Wilhelm Traeger emphasise its threefold nature again. Ried lies on an important transport and mail route. In the 17th century, the post office became a staging post on the “Ordinari”, as the mail coach route was known. This mail route was also the reason important figures such as Pope Pius VI, Emperor Leopold II and Emperor's daughters Marie Antoinette and Marie Luise broke their journey here in Ried on their way to France. Napoleon took lodgings in number 7, Hauptplatz in 1804 and 1809. An attempt on his life was allegedly narrowly prevented here.