Re: [anti-spam-wg] About DNSBLs vs greylisting - Was: Steve Linford and Spamhaus Internet Terrorists

  • From: Esa Laitinen <esa.laitinen@localhost
  • Date: Wed, 23 Aug 2006 09:24:14 +0200

On Tue, Aug 22, 2006 at 12:35:42PM +0200, pna.lists wrote:
> Even those incompatible servers (GroupWise) are able to understand 4xx
> messages -- the current versions are fixed.

Yeah. But do everybody run the current versions?

> >Or people configuring their mailservers to try delivery just once, or
> >mailing-list services than do not use to keep queues for performance
> >reasons.
> 
> Are lame senders' administrators an excuse???

These are no excuses, but realities. The mail needs to get 
delivered. If there are lame administrators, we have to take that 
into account.

And it is easy for an outsider to say somebody is a lame 
administrator. It is one thing to run a mail server with a few 
thousand users, and quite another to run a server hosting mailing 
lists that deliver hundreds of thousands, if not millions messages a 
day.

A system I use does a resend generally 12-24 hours after the first 
delivery try for performance reasons. This quite often trows off the 
greylisting. Which admin is lame, the one that uses greylisting, or 
the one that has config which delays the retry? IMHO the greylister.

> You can use /24 address range instead of a single IP address in your
> greylisting triplets and/or you can store sender domain instead the
> sender e-mail address (from the SMTP envelope).

But the retry doesn't necessarily come even from the same ISP!


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