henpat wrote:

Thanks but it doesn't help me.

Perhaps, but you haven't described anything that I would consider a problem.
Perhaps I sinply don't understand the issue.

I search a solution to my trouble. I know how Exchange/OWA and
Outlook works
I need to change now the language in Outlook but I don't know if I
need to do it in server side or in client side.

You said "set up a new language in OWA" in the subject of your original post
and in the body of that post said:

In a new laptop with settings US-EN by default, the OWA is in English but
the Mialbox is always (Boîte de réception) with all content in French.

I simply don't see what you think is wrong with this. Naturally on an
English WIndows using English IE, the menus and so on will be in English and
if you're viewing the contents of a French-based Exchange server, then what
you see on the server will be in French, or so it seems to me. I just don't
understand what you consider incorrect about that. Moreover you say, "How
can I change it?" without saying what it is you wished changed and then you
go on about the mail profile, but Outlook Web Access doesn't use a mail
profile, so I'm not convinced you _do_ know how Outlook works, but even if I
concede that, you haven't said what you'd LIKE to see or why you believe
what you see is wrong.
--
Brian Tillman