Re: [ietf-smtp] broken signatures, was Curious

[Steve Atkins <[e-mail]>]

On 22/07/2020 19:55, John R Levine wrote:
>>    > That's not gpod advice. The point of the mystery headers is to tell
>>    > what happened to the message during its trip, and the part of 
>> the trip
>>    > before it hit the list manager is as important as the part 
>> after. When
>>    > I'm trying to figure out why something undesirable leaked 
>> through the
>>    > list manager, I need the original headers to figure out what 
>> happened.
>>
>> Right. You need the standard "Received:" lines, which would be a known
>> header at this point, so it would remain.
>
> Really, I find the other stuff to be useful.  I understand that you 
> don't, but you're not the only one here.

Autoresponders and list managers that snip out headers they don't 
understand, particularly those that were added as part of a 
belt-and-braces attempt to avoid mail loops and message amplification, 
can cause problems.

Those not-described-by-RFC headers - e.g. "X-BeenThere: 
[e-mail]" - are not just useful for manual diagnostics, but 
also for automated mitigation of operational problems.

Cheers,
   Steve