I completely fail to see how the availability or nonavailability of DNS fallback behavior will lead to increased spam abuse. As I pointed out previously, if spammers percieve an advantage to sending directly to hosts named in A/AAA records they are going to do so no matter what. By the same token, if they don't perceive an advantage they won't do it.
I see that I have been completely unable to explain myself. I give up. R's, John
