[Exim] Rewrite problem

Hi

I have a probelm:

Im try to set up exim to rewrite the sender address for all the users who using the server.
Its working with loacl delivery, but isnt with SMTP (i already checked the documentation, but cannot find how to do).
What i would like to do is:

mail from user@??? sand as user@??? and
mail from user@??? send as user@???

Im using the following rewite rules

 *@onedomain.com    me@???    bcfrF (this one works fine in the local delivery)
 ^sender@???    sender@???    bcfrFS

Can anybody help me ?

Alma