[CentOS] restrict postfix to only certain users getting incoming mail

[John Doe]

From: Bob Hoffman <bob at bobhoffman.com>

> Postfix, by default, accepts all incoming mail to any user listed in the 
> shadow/passwd and alias files.
> I cannot find a way to stop that without manually blocking each non 
> wanted user (like nobody, apache) without killing local delivery.

What about using /etc/postfix/access:
  root at yourdomain REJECT
Wouldn't that work?

JD