[exim] How to receive message root user

Hello,
In the file log mainlog of my smtp exim server, I have all the time the
following line :


2007-08-13 13:06:57 1IJuhx-0000wF-D3 == root@??? R=localuser
T=local_delivery defer (-52): Retry time not yet reached


I believe that the server try to send a message has the user
root@??? but he does not arrive because there this user does
not exist. I have create a user root@??? and I put one alias so that
these message is to redirect at the level of my limps e-mail.
I cannot create a user root@??? because the name of domain
is contect.net and ixmail is the name of the server on which is installed
exim.
My question is how is that exim consider ixmail.contect.net as
contect.netso that I can receive messages intended has the root user.
Either exists it
another means?

Thank you.