Help with a ?bug? on a web site that we are building on wordpress

We are looking for a code to be able to receive a contact form on all email accounts (hotmail,Gmail, outlook PC + MAC, Mail MAC…..)
Here is my problem… when I send a message via the (contact form) with web site on WORDPRESS, on Outlook on a PC. When we receive all the french accent do not appear ?!?!
The thing is that all our files in the contact form are in utf8. But it seams that somewhere some thing “bugs the content…”

Here is an exemple:
please confirm that the accents that are bellow are appearing ok
l\’affichage des accents suivant est ok
??? ?¨?a???§
Merci et bonne journ??e!

Should be :
svp nous confirmer que l’affichage des accents suivant est ok
é à è ê ? ?
Merci et bonne journée!

HELP !!!