I have Sendmail setup to relay through a Smart host. When I send a message, w/o a domain name appended, it attempts to deliver to a local account. Is there a way to configure Sendmail to automatically append a domain name to the username?

# sendmail -bv scott
scott... User unknown

I want Sendmail to automatically assume @domain.com and to go ahead and send it out through the Smart host, as it does all other email. Does my question make sense?