[exim] SMTP error from remote mail server

When I send mail from root to SMTP server in log file and Mail Delivery
I see this report:

  lshulov@???
    SMTP error from remote mail server after RCPT 
TO:<lshulov@???>:
    host mail.arabellasw.com [xxx.xxx.xxx.xxx]: 550 cannot route to 
sender address <root@???>

What can I change in config files to resolve this problem?

I googled over the world and searched

http://www.exim.org/mailman/listinfo/exim-users

but don't found solution.

Tanks for the help.

Leonid