If you looking to make better condition for your "DNSBLs, RHSBLs,
DCC/Pyzor/Razor", you have just to put every mail coming to your
domain in some kind quarantine system for the same 2 hours and check
this cage regulary.
That's the *last* thing you want to do, because to do that, you have to send
that dreaded '250 OK' as a response to DATA to the remote end - and then you
get stuck with having to deal with bouncing to a possibly forged/bogus MAIL
I cannot agree with you. If you really trust into your anti-spam system, your
just have to discard/bounce spam message with or without notification of
target and/or source user.
When your system decide to reject message as it consider it as SPAM what
would have to do remote system? Bah... exactly the same as that what you
refusing to do: it will generate bounce.
I still have a lot of trouble to get why lot of peoples on this list try, in
way, to move there decision responsibility on remote system.