Milter-greylist

One of the faculties at UW which implemented greylisting for their
local mail service found their users are generally content with it, but
there are several noisy exceptions.  They received enough requests to
opt out of greylisting that their computer support staff requested a
simple mechanism that users can use to opt out without a sysadmin's
intervention.

The attached patch and new source file for milter-greylist 2.0 checks
for the existence of a file named .nogreylist in the recipient's home
directory and whitelists mail to the associated address if the file
exists.  This works well for mail addressed directly to users
(including addresses of the form user+detail@host) without mailer
tables or aliases, in the case where user home directories are
available on the mail server.

Once milter-greylist has a back end for whitelisting from a source we
can let users update directly, we'll probably drop this patch.  In the
meantime, it cuts down on the day to day work load for our support
staff.

--
Dawn Keenan, Information Systems and Technology
University of Waterloo, Waterloo ON