Milter-greylist

Chris Hoogendyk wrote:
> I would not recommend this however.
> 
> Student dorms and such are a great source of viruses. We typically find
> the authorized mail server that corresponds to a domain and whitelist
> that IP address. Even within our own university we are very restrictive
> about what IPs are whitelisted.

*shrug*.. I wasn't questioning the how or why of it, I was merely explaining how
to do it.


That said, out here on the commercial side very few of my spam and virus
messages come from hosts with RDNS's pointing into .edus. Most of mine come from
hosts with no RDNS at all, or with RDNS's pointing to cable/dsl home-user
networks, and networks in APNIC.

YMMV, but I don't greylist .edu's at present. I do selective greylisting, and
only greylist hosts that look like one of the above 3 critera. My default is to
whitelist everything else.

Really, your choice about what to greylist and what not to greylist is a
function of your usage. If 90% of your legitamate mail comes from .edus and is
time-critical, it may make sense to whitelist them.

For me, I have time-critical mail coming from all over the place, so I only
greylist selectively. (And do so as an alternative to outright blacklisting)