Re: [Emailcore] Retrying delivery on post-DATA permanent error status

Weighing in, the wording SHOULD might be appropriate in context of a CLIENT, eg outbound spam filtering, your SMTP server returns 5xx, you should not click send again ;), you might have selected wrong outbound server as well. To say MUST, is impossible to enforce, programmatically given the wide range of possibilities that caused it

On Tue, 26 Jul 2022 01:15:39 -0400
John C Klensin  wrote:
> 
> 
> --On Monday, July 25, 2022 16:52 -0400 "Luis E. Muñoz"
>  wrote:
> 
>> 
>> RFC-5321 has this to say regarding status codes returned
>> post-DATA
>> 
>>    When an SMTP server returns a permanent error status (5yz)
>> code after    the DATA command is completed with
>> ., it MUST NOT make    any subsequent attempt to
>> deliver the message.  As with temporary    error status codes,
>> the SMTP client retains responsibility for the    message, but
>> SHOULD not again attempt delivery to the same server
>> without user review of the message and response and appropriate
>>    intervention.
>> 
>> I do not understand the reasoning behind the "SHOULD not", as
>> I believe it should rather be a "MUST NOT" to maintain
>> consistency. What am I missing?
> 
> (Personal opinion, not as editor or anything else because I
> don't remember the original discussion any more). 
> 
> The key part of that text is the last part of the sentence:
> "without user review of the message and response and appropriate
> intervention".  Now the question for you is "are you sure those
> are all of the cases".  If, for example, for some messages, and
> automated review would be satisfactory, do you think whatever
> robotic process was involved would constitute "user review".  If
> the answer to either of those questions is "no", then SHOULD is
> appropriate and the question becomes whether there should be an
> explanation in the text about those other possible cases.  (Now
> slipping my editor hat back on, for this case, I hope not.)
> 
> best,
>    john
> 
>  
> 
> -- 
> Emailcore mailing list
> Emailcore@ietf.org
> https://www.ietf.org/mailman/listinfo/emailcore
> 

--
-- 
"Catch the Magic of Linux..." 
------------------------------------------------------------------------ 
Michael Peddemors, President/CEO LinuxMagic Inc.
Visit us at http://www.linuxmagic.com @linuxmagic
------------------------------------------------------------------------ 
A Wizard IT Company - For More Info http://www.wizard.ca 
"LinuxMagic" is a Registered TradeMark of Wizard Tower TechnoServices Ltd.
------------------------------------------------------------------------
604-682-0300 Beautiful British Columbia, Canada