Gmail running our email domains

Wouldn't it be cool if Gmail ran our email domains? I've got my own domain jguk.org, that could just forward the email onto my Gmail account, but Gmail could actually run the domain's MX record and then have the ability to better manage spam email. Employing techniques like issuing SMTP's Reject 554 code for hosts connecting which were known to send spam or if the incoming email looks like it's definitely spam.

Sending the Reject code means you refuse to take and pass on this spam email, I prefer this approach to accepting all email and then sorting and storing spam in a Junk folder, as then I've still got to sift through all those Junk emails to double check. I read my email using Thunderbird on my laptop, but that's not as portable as I'd like, and I still get junk mail slipping through like these:

(Thunderbird's Bayesian filters does a good job of classifying junk mail which does get through!)

Therefore, spam prevention and rejection decisions need to be taken during the SMTP session when computers connect, dramatically cutting out the market for spammers. David Mazières's MailAvenger implements these ideas which should reduce spam.

If anyone from Google is reading this, how about adding a feature to host our MX records directly with you? Then there could be a simplified one stop spam rejection system put in place, rejecting connections and emails determined spam before Gmail takes responsibility for them. This would require a performance intensive change to perform tests during the SMTP session, but is definitely doable with one of the clusters Google has!

One final idea, why not use a Domain Ranking system coupled with SPF checks to maintain tuned weights which give an indication of how likely a particular domain is to be sending spam.

Update: Google have already had part of this idea, they provide a Hosting service which could be used. Not sure if the MailAvenger style anti-spam measures idea is integrated h it.