Mail sent through tem'post are part of the postal history of France, despite their philatelist receiver putting them in the paper trash. tem'post is a service of La Poste dedicated to big sender of bills, mensual listings or social checks.
This week, I had a thought for those who are trying to follow this history of the contemporary postal service when I discovered that the proof of franking is on the inner correspondance, not on the cover.
When EDF (French former electricity monopoly) and a large part of firms print the tem'post mark on the cover, the MGEN (a professional social security service) print it on the letter, just above the receiver's adress.
Like amateurs of classical covers, the correspondance will always be as interesting as the cover for the historian.