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Re: greylisting done at end of headers, or end of daya (QUIT) ?

2007-01-30 15:25:15

Keld Jørn Simonsen wrote:
On Tue, Jan 30, 2007 at 02:50:21PM -0500, Tony Hansen wrote:
Keld Jørn Simonsen wrote:
I am applying greylisting and it really has some effects on the amount
of spam coming in.
...
So I ask you: would greylisting based on some unique id like Message-id:
lead to a better result?
You're making a few assumptions: 1) There will *be* a message-id you can
key off of. 2) The zombies will use different message-id values for each
message. I don't think either of these assumptions would necessarily
hold true.

yes, I can imagine this. But maybe you could use some sort of other unique
identification like a md5sum of the body, or md5sum of the
header or some such?

I'm sure you'd be better off.

And why does the FreeBSD people rely on message-id: if this may not
work, as you indicate?

For the case of missing message-id's, perhaps they wind up not accepting
*any* messages without a message-id, under the assumption that only
illegitimate mail would be missing them, and that's ok because it's
illegitimate mail you're trying to block.

and would it improve the situation?

It's guaranteed: your mileage *will* vary. :-)

        Tony Hansen
        tony(_at_)att(_dot_)com