[CentOS] spam control

[Feizhou]

> First, I'm using exim.  No particular reason for this other than I
> know how to use it and even after many years hacking sendmail, I
> still find it easier to work with exim :)  Now if I just had the
> time to get exim to play nicely with vpopmail...

easy. Use maildrop as your LDA. maildrop can be used as the glue between 
postfix and vpopmail. You can do the same for exim. But if you want to 
make use of the dot-qmail files...that is another story.