[67268] in North American Network Operators' Group
Re: greylisting
daemon@ATHENA.MIT.EDU (Suresh Ramasubramanian)
Fri Feb 6 22:20:00 2004
Date: Sat, 07 Feb 2004 08:49:12 +0530
From: Suresh Ramasubramanian <suresh@outblaze.com>
To: Ken Leland <kwl@shell.monmouth.com>
Cc: nanog@merit.edu
In-Reply-To: <20040206204113.GA21685@shell.monmouth.com>
Errors-To: owner-nanog-outgoing@merit.edu
Ken Leland [2/7/2004 2:11 AM] :
> On Fri, Feb 06, 2004 at 01:40:14PM -0500, Dmitri Krioukov wrote:
>
>>can someone provide any comments on greylisting?
>>how effective is it, etc?
>
>
> we have 20 regex expressions that block mail directly from a
> reverse dns that "looks" like a consumer broadband connection.
> Then we have to maintain a whitelist on a case by case basis.
Er, I think you and Dmitri are talking about different things.
From a mail operations standpoint, I am not a big fan of graylisting,
because even legitimate senders get 4xx'd for a while, the first time
they send mail.
When any such strategy means that someone else's mail queues are filled
with timed out emails waiting for retransmission, it d not be rocket
science to see why this just doesn't scale too well.
--
srs (postmaster|suresh)@outblaze.com // gpg : EDEDEFB9
manager, outblaze.com security and antispam operations
