Addresses should be written as follows:

Monsieur François Micheloud
Micheloud & Cie
Grand-Chêne 8
Postfach 3332
CH-1003 LAUSANNE
Switzerland

In German, Herr means Mister and usually occupies a line by itself. If the letter is addressed to a company, the correct term is Firma (on its own line as well). 

In French, you should write Monsieur or Madame (don’t abbreviate).

GmbH or A.G. (in German) and S.A. (in French) means it’s a corporation.

The street name is followed by the street number.

CH stands for Confederatio Helveticae (official name of Switzerland).

The name of the city is capitalized. Don’t underline it.

If there’s a Post Office Box, write Postfach (German) or Case Postale (French), followed by the number.