My Windows life mail does not render the right French spelling for typical French letters such as é, è à ç as wel as the sign €

How to fix it.

By composing the French text there is no problem. But once I go back in my folder  of Send Messages, my title phrase becomes :

My Windows life mail does not render the right French spelling for typical French letters such as é, è à ç as wel as the sign €

while the subject line remains correct.

How can I make sure the right spelling comes in the email of my French speaking correspondents.