Re: [ietf-smtp] [Emailcore] Proposed ESMTP keyword RCPTLIMIT

George Schlossnagle <george@sparkpost.com> Sun, 18 April 2021 23:47 UTC

Return-Path: <george@sparkpost.com>
X-Original-To: ietf-smtp@ietfa.amsl.com
Delivered-To: ietf-smtp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id B04793A12AB for <ietf-smtp@ietfa.amsl.com>; Sun, 18 Apr 2021 16:47:59 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.198
X-Spam-Level:
X-Spam-Status: No, score=-0.198 tagged_above=-999 required=5 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=sparkpost.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 0Rud3vIdOrHm for <ietf-smtp@ietfa.amsl.com>; Sun, 18 Apr 2021 16:47:55 -0700 (PDT)
Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 3B08A3A12B3 for <ietf-smtp@ietf.org>; Sun, 18 Apr 2021 16:47:54 -0700 (PDT)
Received: by mail-ej1-x62a.google.com with SMTP id w3so50172795ejc.4 for <ietf-smtp@ietf.org>; Sun, 18 Apr 2021 16:47:54 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sparkpost.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=9PP3FJuQf5bP2sXHS8hesKVpx3tt2bZf8nPphDNC3pk=; b=Q7XvWbUdpIzyngsB779HGxobbsmII9ZUXWCvsLO4yiOGmfQlYzk4fjAkcYjNDRVnX/ GCxq72BdeMnMYqP496VubvCFYPzRCi+IVxcCk2t10o9xn0tdJoOfYVUG0dzEGvWtUdPg vNk0w/kOX7v0e0ugeSjtdiz67alHDir9JeEzw=
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=9PP3FJuQf5bP2sXHS8hesKVpx3tt2bZf8nPphDNC3pk=; b=mnV5D8yBqK9qVqtpJy+VTmBRQCRApHDG0JoVeyGR9IDHt42Q7dfToRei1jJwURqqmk uEvtHmsfF2yCIy8yZo/VLBzYCIYQJ5EShKzHwEGyuI+ni/PETDZX9A8gxB7c6sKSQP+M JWMNNdGTHSqJfzqDiHNRe0Mcdx/SJrC/YImsuU3sVu13lIak5jD+74mysdTrREgBRTcj 4d2dgcNT/tYjtURDJyYl3u1djPKbywPGXhG8pJnxM+ebC6i99yyaXM3smYgpgFxQ7G6U lqoU/2cDjHaTla8F7N2qz45RnKOVkIemDmF/3TzeZigSXtBI3kI9FKOIkhFYqA/Dz2cc b5kw==
X-Gm-Message-State: AOAM531D47nbIejEUc5RFdNmRB0f6u3/SXJcBTbyu+vEQNhbfcELpueb MiaqI2xSev2cBb254TxbSsgvYPjCtNHvqIEqPuvtFXdY6w==
X-Google-Smtp-Source: ABdhPJwl2GWM4LgCkwV8pZSnMlwTnJLYKTGifEsQJ6DHqRuXg30qJzilWEMCSxP/90eUGsqqgxITNsHJbhcBTuex4nM=
X-Received: by 2002:a17:906:f9da:: with SMTP id lj26mr18754308ejb.98.1618789670917; Sun, 18 Apr 2021 16:47:50 -0700 (PDT)
MIME-Version: 1.0
References: <cone.1615844513.220592.51342.1004@monster.email-scan.com> <20210315234648.563C0708B340@ary.qy>
In-Reply-To: <20210315234648.563C0708B340@ary.qy>
From: George Schlossnagle <george@sparkpost.com>
Date: Sun, 18 Apr 2021 19:47:15 -0400
Message-ID: <CAO=DXp-+fJwsNegzu3zgwDLtCcSF104AUF=i+_GMgSYVBAKjWg@mail.gmail.com>
To: John Levine <johnl@taugh.com>
Cc: ietf-smtp@ietf.org, mrsam@courier-mta.com
Content-Type: multipart/alternative; boundary="0000000000004d30a105c047d77a"
Archived-At: <https://mailarchive.ietf.org/arch/msg/ietf-smtp/gTLJA77nqXbAEUk56n5GXupIXz8>
Subject: Re: [ietf-smtp] [Emailcore] Proposed ESMTP keyword RCPTLIMIT
X-BeenThere: ietf-smtp@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Discussion of issues related to Simple Mail Transfer Protocol \(SMTP\) \[RFC 821, RFC 2821, RFC 5321\]" <ietf-smtp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf-smtp>, <mailto:ietf-smtp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ietf-smtp/>
List-Post: <mailto:ietf-smtp@ietf.org>
List-Help: <mailto:ietf-smtp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf-smtp>, <mailto:ietf-smtp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 18 Apr 2021 23:48:00 -0000

As a commercial MTA and ESP provider, this proposal is very exciting to
me.  Today we guess at these things and largely guess at things based off
of either observed behavior or out-of-band discussion with those operating
the receiver side of the email exchange.  Having this defined in the
session would be great.

George

On Mon, 15 Mar 2021 at 19:47, John Levine <johnl@taugh.com> wrote:

> It appears that Sam Varshavchik  <mrsam@courier-mta.com> said:
> >MXes which do not announce their limits are going to dominate for some
> time.
> >So, I still need to do this for the foreseeable time. So, what does this
> >SMTP extension buy me? The only thing I can think of: not duplicating
> >messages when I don't need to.
> >
> >But the thing is: I don't recall anyone raising this to me, as a
> problem.
> >This is not on my radar screen as a problem that wants to be solved.
>
> I wouldn't think that your users would be very interested, but bulk
> mailers are desperate for
> any hints about how much mail they can stuff at people without getting
> blocked or rate limited.
>
> R's,
> John
>
> _______________________________________________
> ietf-smtp mailing list
> ietf-smtp@ietf.org
> https://www.ietf.org/mailman/listinfo/ietf-smtp
>


-- 
*GEORGE SCHLOSSNAGLE*
chief evangelist
www.sparkpost.com
(el) george@sparkpost.com