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Re: [ietf-smtp] SMTP status codes 251 and 551

"John Levine" <johnl@taugh.com> Tue, 11 February 2020 02:46 UTC

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Date: Mon, 10 Feb 2020 21:45:58 -0500
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From: John Levine <johnl@taugh.com>
To: ietf-smtp@ietf.org
Cc: george@sparkpost.com
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Archived-At: <https://mailarchive.ietf.org/arch/msg/ietf-smtp/y8NAGxMKCiObRqdXvxYY_oFpdzc>
Subject: Re: [ietf-smtp] SMTP status codes 251 and 551
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In article <CAO=DXp-j4OFwiPqLHvNzQ+dL+CNE0t58AZ33pxaBkBBWce2+NA@mail.gmail.com>,
George Schlossnagle  <george@sparkpost.com> wrote:
>We see a good bit of email here and the number of 551s that seem to
>indicate forwarding is being suggested is incredibly tiny.  I could run
>some stats if you like, but call it < 0.0002% over the past year's bounces.

Thanks.  Do you see any 251 at all?

>Email being what it is, there's lots of use of 551 for other purposes
>(anti-abuse feedback, etc).

Not surprising.  In response to RCPT TO or something else?

R's,
John

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