[Exim] Multiple domain accounts.

Question.
I have a exim mail server running 19 domains on it for 19 diffrent clients.
Now the way that i create accounts is i add normal system accounts with no
login privelages.
This means that is if i am running like domain foo.com and bar.com and a
user mails johnny@??? it will get dropped in johnnys mailbox, and if
somebody mails johnny@??? it will also get dropped in that account.

How can restrict this to a certain domain?
Also how can i create 2 johnnys on my system one for each domain?

Marius Vincent
Technical
ELCB Information Services