Postfix Question

[Dustin Cross]

I am using the default Postfix on Mandrake 8.1 and I want to be able to recieve 
mail for localhost, sandust.org, and sandust.com.  I have tried a few different 
things and nothing worked yet.  I have tried adding the following line 
to /etc/postfix/main.cf :

mydestination = sandust.com, sandust.org, localhost

I get mail for sandust.com, but nothing else.  Does anyone know what I need to do 
to get Postfix to accept mail for these?

Thanks,
Dusty