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Re: [Emailcore] Proposed ESMTP keyword RCPTLIMIT

"Brotman, Alex" <Alex_Brotman@comcast.com> Fri, 12 March 2021 20:12 UTC

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From: "Brotman, Alex" <Alex_Brotman@comcast.com>
To: "dcrocker@bbiw.net" <dcrocker@bbiw.net>, Todd Herr <todd.herr=40valimail.com@dmarc.ietf.org>
CC: "emailcore@ietf.org" <emailcore@ietf.org>, Jeremy Harris <jgh@wizmail.org>
Thread-Topic: [Emailcore] Proposed ESMTP keyword RCPTLIMIT
Thread-Index: AQHXF1bpyUO6yJM1+kqkyKYfbMgVqqqAgPmAgAAD7ICAAARlgIAACEeAgAAT9oCAACI30A==
Date: Fri, 12 Mar 2021 20:11:51 +0000
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References: <ca851fda-63ac-8739-c3eb-bde725aa25f3@isode.com> <c188413b-9337-40d8-8062-9c0f58f6cd98@www.fastmail.com> <CAHej_8kHwEOmq5bf49=Tt6ZEVkuidMhy5s4XPu7JC+k22qraZg@mail.gmail.com> <0F2370D0-D04C-45A1-A5A1-8FF1F174FFE5@dukhovni.org> <CAHej_8=deJU1CW2AzDBu5ji3Uir+_zF6Gp59Z-hHRmRipz8Osw@mail.gmail.com> <9A7BDB22F3A0396EF24BF91D@PSB> <5772045E-2EB3-44B7-BCA8-0135DF809C62@dukhovni.org> <68cd718f-3bf5-3906-25e1-94ecfdb0ba2f@wizmail.org> <5aef8939-092d-b6e9-9662-4599251fb920@dcrocker.net> <05d6b2cb-ae9f-83eb-28cc-b5cee030906a@wizmail.org> <cf2a53f3-3c4c-6453-0868-82f035d68f6f@dcrocker.net> <CAHej_8=EPsVLZsnh1bHLVxVWd-ZY0qB230LiWXJybTii1aKoLA@mail.gmail.com> <36694a3d-6b25-37aa-7c18-a3a1bbba61be@dcrocker.net>
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Archived-At: <https://mailarchive.ietf.org/arch/msg/emailcore/o6RB0_Fi9kpMeaYaX_AoLtKz7bM>
Subject: Re: [Emailcore] Proposed ESMTP keyword RCPTLIMIT
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This may not work well in practice.  It's entirely possible that the number of permitted recipients (or any similar limitation) could change during the session as more is learned about the sender.  Such as once MAIL FROM is sent, the receiver decides that the sender is less trustworthy and will now change the max recipients on a single message.

Also, I realize the receiver could just not advertise this extension.

--
Alex Brotman
Sr. Engineer, Anti-Abuse & Messaging Policy
Comcast

> -----Original Message-----
> From: Emailcore <emailcore-bounces@ietf.org> On Behalf Of Dave Crocker
> Sent: Friday, March 12, 2021 1:04 PM
> To: Todd Herr <todd.herr=40valimail.com@dmarc.ietf.org>; Dave Crocker
> <dcrocker@bbiw.net>
> Cc: emailcore@ietf.org; Jeremy Harris <jgh@wizmail.org>
> Subject: Re: [Emailcore] Proposed ESMTP keyword RCPTLIMIT
>
>
> > On Fri, Mar 12, 2021 at 11:23 AM Dave Crocker <dhc@dcrocker.net
> > <mailto:dhc@dcrocker.net>> wrote:
> >
> >     On 3/12/2021 8:07 AM, Jeremy Harris wrote:
> >      >
> >      > Certainly.  Did you have a case in mind that isn't covered by
> >      > the above two parameters?
> >      >
> >      > (I should have specified "taking one or more parameters from the
> >     list...")
> >
> >     [snip]
> >     max number of characters for total message
> >
> >
> > Don't we already have this with SIZE?
>
>
> So, you are saying that it was a good idea for me both to list a variety of
> possibilities and to note that I wasn't advocating for any of them but merely
> meant them as examples?
>
> I agree...
>
>
> d/
>
> --
> Dave Crocker
> Brandenburg InternetWorking
> bbiw.net
>
> --
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> Emailcore@ietf.org
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