When writing letters to France, the only thing that should appear on the front of the envelope is the recipient's address - and of course the postage.

Write it in the center of the envelope, leaving at least 15mm space between the address and the bottom edge of the envelope (for the French Post Office's printed barcodes). You should include the recipient's name (line one), street address (line two), zip code followed by city (line three), and country (line four). Be sure to capitalize all nouns, such as street names and cities. You can find more information about correct addressing here.