On 2011-05-30 5:02 PM, Steve wrote:
> Maybe only the mail servers that wan't to be recognized and not allow others
> to email on their behalf will register a record? 

Not trying to sound rude, but you can probably find all the answers to
your questions at:
http://www.openspf.org/

In particular, you should read the page about forwarding mail:
http://www.openspf.org/SRS

-- 
Neil Herber