What is the best way to setup sendmail to treat a range of adresses on
a single domain as local, but 1 or two exceptions as non local?

In all cases a local user exists for each email address, but i want to
"locally" deliver mail for all the desk bound people, but "externally"
deliver mail for the "mobile" people.

Our email and domain is hosted externally (example.co.za) and mail is
fetchmailed from mail.example.co.za. Sendmail on my local server sends
mail via smarthost.

If i define example.co.za as a domain i receive mail for, then ALL
mails are delivered locally - including the mobile ones, not good

If i dont define the domain, then all go out via smarthost, even after
adding the "local" mails in virtusertable (using
"brian@example.co.za brian" ) I was hoping that they would be
mapped to the local user by virtue of the virtusertable, but so far no
good.

I am using Fedora core 4 with Sendmail 8.13

Any would be appreciated