[geeks] Greylisting?

[Mike Meredith]

On Tue, 22 Nov 2005 11:59:46 -0600, Michael Parson wrote:
> I know it's being used by large and small organizations alike.

So? Just because people use it doesn't make it good. Some people like
challenge-response; anyone with any sense will see that it doesn't
scale. Greylisting isn't as bad, but it has a very similar scaling
problem.

> Including one of the largest universities in the US.

Which doesn't impress me. Somehow *I* have wound up in charge of the
mail servers (well the Internet-facing ones) at a medium-sized UK
Univeristy. Universities don't run large mail servers; at least not in
comparison to ISPs.

> > Mail servers are at their most efficient when they can hand off
> > mail to the destination server immediately. Waiting for the next
> 
> legitimate mail.  The whitelisting feature of the greylist minimizes
> the amount of mail that is kept for the next queue run.  For example,

So what you're saying is that you don't see it can cause a problem ?
Well people who manage large mail servers *do* think it could cause a
problem. Do you know more about running large mail servers than they do
? I certainly don't claim to.

> The old "be conservative with what you send, liberal with what you
> accept" policy.  

So? Old != wrong.

> For now, I think asking legitimate mailers to knock twice before I
> accept is a small burden.  If enough mail servers out there picked up

You're still ignoring the point. It's a small burden that you shouldn't
be inflicting on others when there are other methods that work just as
effectively. Adding a small burden to communicate with each site just
won't scale.