The post horn was a wind instrument used by postal couriers to signal the arrival of mail. This tool can describe the mail delivery activity from the sixteenth century to the nineteenth century and specifically the work done by the Tasso in the transmission of letters, documents and small parcels. In the organizational system of the transmission of information between the fifteenth and sixteenth centuries, the Tasso family established themselves by managing the Habsburg post office at the service of characters such as Emperor Maximilian I of Habsburg and Charles V. The family thus found itself organizing the postal service for the emperors on an increasingly extended territory, which covered almost all of Europe. Thanks to the large economic resources made available to the Tasso by the Emperors, the taxi couriers were able to organize a delivery service based on relay races for which the courier and horse, after traveling a maximum of 20 km, had to be replaced. The operation took place quickly, because the postmaster, the owner of the post office, had already arranged the change. This happened because the courier, as he approached the post station, blew the post horn, the postmaster recognized the sound and prepared the horse, courier and correspondence for the change. The post horn is identified with the speed of the service carried out by the Tasso: a letter from Brussels to Paris, in 1516 in the summer, was delivered in a day and a half. Furthermore, behind this tool there is the organizational world of the Tassian company and of modernity with which the family was associated. The Tasso were defined as the organizers of the modern European postal system, both for the speed with which they organized exchanges, and for the organizational skills of a service managed as a multinational, and because, for the first time, places, days and stable times of departure and arrival of the post office. The Badgers united Europe through communication in unsuspecting times and the post horn, still a symbol of the post office in many European states, tells all this.