On Fri, 28 Jan 2022, Bill Cole via Exim-users wrote:
> On 2022-01-27 at 14:31:41 UTC-0500 (Thu, 27 Jan 2022 19:31:41 +0000 (GMT))
> Andrew C Aitchison via Exim-users <andrew@???>
> is rumored to have said:
>
>> On Thu, 27 Jan 2022, Marcin Gryszkalis via Exim-users wrote:
> [...]
>
>>> - What do you think about implementing re-folding headers to make mail
>>> RFC-compliant again (ie. fix what outlook spolied)?
>>
>> Unfortunately that can break DKIM signatures.
>
> True, but only if the signer is using 'simple' header canonicalization, in
> which case they surely must expect and so deserve to have their signatures
> broken.
>
> Yes, I'm MOSTLY serious.
Ah.
Now I have my head around header canonicalization I agree and am relieved;
we don't need to worry too much about breaking DKIM.
Would we need a setting to say whether to break or reject messages with
simple header canonicalization and long headers, or is it clear which
we should do ?
--
Andrew C. Aitchison Kendal, UK
andrew@???
