Milter-greylist

Hi,


I'm new to the list. I've been running Milter-Greylist for several 
months to try to cut down on spam received by an address which for 
various reasons must be published on the web. I've noticed that some 
spammers are using a particular format for their mail from: addresses 
E.G. mydomain.com@... or 
myaddress=mydomain.com@.... I've been having 
Milter-Greylist reject these messages at the rcpt stage, but some of 
these messages are still getting through. Recently I discovered that the 
reason they're getting through is that the actual spammer servers are 
allowed to send mail from their spammer domains based on SPF records, so 
Milter-Greylist bypasses all filtering upon seeing valid SPF. Normally 
this is a good thing, but in this case I want their spammy junk 
rejected, I don't care if their SPF claims they're the President, the 
Pope, and the deity of every religion which has ever existed, all rolled 
into one.


I read about the nospf keyword you can use in acl statements, but I have 
one concern. Will using nospf in an acl disable SPF checking completely, 
for all messages, or just for messages that match that particular acl? 
This seems like the solution if SPF checking can be disabled on a 
case-by-case basis.

Thanks for any help,


Jayson