Milter-greylist

According to manu@...:
> Do you think it would buy us something to keep record the the number of
> delivery attempts before a message gets accepted?

I've coded that a while ago in 2.* (but lost it when I recently upgraded to
3.1.5+cvs).

My patch added an additionnal field in the db that was reported in the logs.
I was useful to fine tune the delays. I was also able to classify the
botnets based on their retry mechanisms.

I never posted the patch as it made the db backward incompatible
and I know you hate that.

/Fabien