[Plugin: Contact Form 7] No confirmation “Email sent”

Hello
first, i’m not english, so excuse me :p

I’ve installed contact form 7 into my wordpress here :

https://espacebiologique.free.fr

And, if you try to send a test email, you’ll see the problem. When we click on “send”, the little thing turn, turn, turn ans nothing, no confirmation like “You email was succefully sent” appears. but the mail is received.

How to fix it ?

Ps: I understand english better than i talk ??