[exim] 1 user name in 2 different domains

Hi,

I'm running exim 4.20 on redhat with 2 domains :
for exemple toto1.com and toto2.com
I have created one user named user1.

When I send an e-mail to user1@??? or user1@??? it goes in the
same mailbox : user1
My problem is that I need to have 2 different mailboxes : One for
user1@??? and another one for user1@???.
I didn't found how to solve that problem ?

Any idea ?? ;-)

JPB