I've recently updated to Postfix 2.1.4 (from 2.0.16), and implemented the built-in SPF checking stuff (through the policy mechanism). I quickly found a bug in Meng Wong's code, where it checks mail that's being relayed (via SASL authentication). Nasty.
Since I didn't want my SPF record to include all of the places where my
users might send from, I updated the code to add:
if (!$attr{sasl_method}) {
Before the call to
Mail::SPF::Query. I ended the conditional after the line which returns
"dunno". Now it bypasses the SPF check for authenticated users, so my users can use the system, and all incoming mail will get checked. Much better!