Re: [ietf-smtp] EHLO domain validation requirement in RFC 5321

Sam Varshavchik <> Sun, 04 October 2020 17:31 UTC

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From: Sam Varshavchik <>
Date: Sun, 04 Oct 2020 13:31:18 -0400
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Subject: Re: [ietf-smtp] EHLO domain validation requirement in RFC 5321
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Arnt Gulbrandsen writes:

> On Sunday 4 October 2020 11:49:29 CEST, Keith Moore wrote:
>> Please cite these "well established anti-abuse metrics" because they should  
>> not be accepted as valid without question.
> Actually, a significant set of email senders do question and do not accept  
> them, so you're in a lot of company here, even if it may not be very good  
> company ;)
> But there's another aspect. Who accepts? These things are the content  
> of .procmailrc files and sieve scripts. Who has authority to accept or not  
> accept the validity of what I write in my sieve script? I believe that's a  
> local matter, out of scope for the IETF, and therefore off-topic for all  
> IETF lists.

Actually, this stuff is frequently checked during SMTP, and an undesirable  
result results in a rejected EHLO, MAIL FROM, RCPT TO, or even DATA. The  
original subject matter of this thread, the EHLO domain validation, is  
rarely done in a post-receipt phase, like in .procmailrc.

But your question is equally valid: who has the authority to accept or not  
accept the validity of how I configure my mail server with respect of the  
criteria it uses to accept or reject public E-mail? And this seems to be on  
topic, since the current document seems to require someone to accept the  
validity of certain parts of SMTP, and prohibit those bits from being used  
to determine that the E-mail is unwanted, and reject it.