Milter-greylist

> I have my greylisting set for 10 seconds and autowhitelisting for 30
> days. The spammers who never try - well, they never retry. It doesn't
> matter what the greylisting time is set for. Why needlessly delay the
> MTAs that _are_ going to retry?

What I'd really like to do is simplify the triplet ...
so instead of "from@... + smtp.sender.com + user@..."
we could have "[from] + smtp.sender.com"
where "from" is only needed if sender.com has 4+ MX records
(or some other simple check for a big company/service).

I don't care about which of my users get the mail because my users are all
aware of each other; the only case in which user@... is of use
is for a large-scale deployment like an ISP or university ... and even
then, I might argue it's not worth the minimal gain, especially given
other enterprise spam-fighting tools.

Another potential feature would be to utilize SPF (though not blindly as
the milter-greylist option does) in the following manner:  if
smtp.sender.com is listed in SPF, add all servers listed by SPF in the
autowhitelisting.  This would solve the issue created by redundant smtp
servers (whose extreme case is exhibited by gmail as noted earlier).

I unfortunately lack the time to help write such a modification :-(

-Adam