[Greylist-users] greylist lib in C? + several Q's

[Ken Raeburn]

Graham Toal <gtoal at gtoal.com> writes:

>> Try explaining that to the people at Yahoo Groups.  Try explaining to
>> your users that Yahoo Groups misbehaves, and therefore isn't allowed
>> to send them email.
>
> So what's the deal with Yahoo?  I hadn't heard that before.

Yahoo Groups doesn't retry messages after temporary failures.  (Yahoo
email accounts may be different, this is Yahoo Groups, for mailing
lists.)  At least, that's the comment in the file with whitelist
recommendations in Evan's package.  Southwest Airlines and Ameritrade
also do that, and some sites use a unique sender id per delivery
attempt.  Some just do unique sender ids per message, causing a delay
for every message (though many people, including me, have worked up
patches to deal with certain patterns of sender ids).

>> > Are you a business?  If so, then it is a cost/benefit analsys.
>
> No, a University, and very sensitive to complaints from faculty
> about important mail going missing or being delayed.  Basically if
> I implement anything that has the *potential* of delaying important
> mail, from that day on, anything that anyone screws up such as not
> submitting a grant application in time is going to be down to
> my anti-spam code, whether that was the culprit or not.  So I
> am taking a conservative approach and doing enough Quality Assurance
> on it that I know we're on a sound footing.

I work at a university also, though not in the group that deals with
the mail server.  I've tried to get them to consider Greylisting, but
the most positive comment I got was that it wasn't "mature enough".

Other comments were that when important mail gets delayed, users get
pissed off at the postmasters of either or both sites, regardless of
advertised policies and which site actually caused the delay, and they
don't want to deal with that.  I guess having users generally pissed
off about the level of spam in their mailboxes is preferable.

And turning on greylisting in a learning mode (recording triplets but
not tempfailing any mail) or as an experimental service (with all
recipients whitelisted except a few who knowingly accept the risk of
delayed or lost mail) would probably cause a slight net increase in
resource usage, when our mail servers are already overloaded.

So they aren't going to be doing Greylisting any time soon. :-(


When you get the results of your QA work, please post plenty of
details, good and bad, for those of us who would like to point our
local sysadmins at them.

Ken