Re: [Asrg] [ASRG] SMTP pull anyone?

"Chris Lewis" <clewis@nortel.com> Tue, 18 August 2009 17:17 UTC

Return-Path: <CLEWIS@nortel.com>
X-Original-To: asrg@core3.amsl.com
Delivered-To: asrg@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id D263928C31B for <asrg@core3.amsl.com>; Tue, 18 Aug 2009 10:17:39 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -5.11
X-Spam-Level:
X-Spam-Status: No, score=-5.11 tagged_above=-999 required=5 tests=[BAYES_05=-1.11, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qJjLqnf9nqzR for <asrg@core3.amsl.com>; Tue, 18 Aug 2009 10:17:39 -0700 (PDT)
Received: from zcars04e.nortel.com (zcars04e.nortel.com [47.129.242.56]) by core3.amsl.com (Postfix) with ESMTP id DDB933A6B5A for <asrg@irtf.org>; Tue, 18 Aug 2009 10:17:38 -0700 (PDT)
Received: from zrtphxs1.corp.nortel.com (zrtphxs1.corp.nortel.com [47.140.202.46]) by zcars04e.nortel.com (Switch-2.2.0/Switch-2.2.0) with ESMTP id n7IHFWQ05065 for <asrg@irtf.org>; Tue, 18 Aug 2009 17:15:33 GMT
Received: from zrtphx5h0.corp.nortel.com ([47.140.202.65]) by zrtphxs1.corp.nortel.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 18 Aug 2009 13:17:33 -0400
Received: from [47.9.16.79] (47.9.16.79) by zrtphx5h0.corp.nortel.com (47.140.202.65) with Microsoft SMTP Server (TLS) id 8.1.340.0; Tue, 18 Aug 2009 13:17:32 -0400
Message-ID: <4A8AE22C.7030300@nortel.com>
Date: Tue, 18 Aug 2009 11:17:32 -0600
From: "Chris Lewis" <clewis@nortel.com>
Organization: Nortel
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.22) Gecko/20090605 Lightning/0.9 Thunderbird/2.0.0.22 Mnenhy/0.7.6.666
MIME-Version: 1.0
To: "asrg@irtf.org" <asrg@irtf.org>
References: <922a897b0908170253k60c0d57dh5e593c78f9137fab@mail.gmail.com> <4A8ADB9D.5080004@billmail.scconsult.com>
In-Reply-To: <4A8ADB9D.5080004@billmail.scconsult.com>
Content-Type: text/plain; charset="ISO-8859-1"; format=flowed
Content-Transfer-Encoding: 7bit
X-OriginalArrivalTime: 18 Aug 2009 17:17:33.0889 (UTC) FILETIME=[C6759B10:01CA2027]
Subject: Re: [Asrg] [ASRG] SMTP pull anyone?
X-BeenThere: asrg@irtf.org
X-Mailman-Version: 2.1.9
Precedence: list
Reply-To: Anti-Spam Research Group - IRTF <asrg@irtf.org>
List-Id: Anti-Spam Research Group - IRTF <asrg.irtf.org>
List-Unsubscribe: <http://www.irtf.org/mailman/listinfo/asrg>, <mailto:asrg-request@irtf.org?subject=unsubscribe>
List-Archive: <http://www.irtf.org/mail-archive/web/asrg>
List-Post: <mailto:asrg@irtf.org>
List-Help: <mailto:asrg-request@irtf.org?subject=help>
List-Subscribe: <http://www.irtf.org/mailman/listinfo/asrg>, <mailto:asrg-request@irtf.org?subject=subscribe>
X-List-Received-Date: Tue, 18 Aug 2009 17:17:39 -0000

Bill Cole wrote:

> I don't see how this reduces the effort required on the receiving side in
> comparison to currently common practices.

Precisely - in fact, it increases the work the receiver has to do, 
probably substantially.

Consider: the offer/callback approach is identical to SMTP up to the 
DATA keyword.

The "offer" would have to have more-or-less the same information as the 
pre-DATA SMTP information in normal SMTP.  A SMTP server can just as 
easily reject on that data pre-DATA, as to "choose not to do" the call 
back.  So, up to this point, the offer/callback approach doesn't do any 
less work than normal SMTP.

Then offer/callback actually has to call back and retrieve the message. 
  You also have to build in mechanisms to make sure that someone _else_ 
isn't doing the retrieval.

Then, if you do any DATA filtering, _both_ approaches have to do similar 
levels of work.

In other words, the offer/callback approach only causes you to expend 
more work actually implementing the callback _itself_, plus checking it 
for validity.