Milter-greylist

On Thu, Oct 13, 2005 at 02:13:44AM -0400, Matt Kettler wrote:
> This is really only a problem for "normal" sendmail users. ie: those who don't
> relay, have local accounts, and don't mitigate dictionary attacks.

Like me. The easy way out of this (which I implemented) is to
enable greylisting only for existing users (acl greylist rcpt ...)
and have a default whitelist clause (acl whitelist default).
Non-existant recipients will be whitelisted immediately
by milter-greylist, and sendmail will reject them at once.

The "acl greylist rcpt ..." lines for greylist.conf could be
generated automatically, but in fact it's not a problem if
you do this only from time to time, as for new users it 
tends to take some time until they collect big amounts of spam.

mp.