Milter-greylist

I would like to whitelist email received from a DNS address 
(foo.dynip.com) which resolves to a dynamic IP address (and possibly a 
different one the next time you look).

How do I do this?

Also, what is the difference between greylist.conf commands acl, racl, 
dacl?  The web page http://linux.die.net/man/5/greylist.conf doesn't 
mention the latter two commands.  Where else should I look?

-- 
_______________________________________________________________
Bob Smith - bsmith@... - http://www.sudleyplace.com