On Thu, Nov 18, 2021 at 11:36:53PM +0300, Odhiambo Washington via Exim-users wrote:
> On Thu, Nov 18, 2021 at 12:32 PM Evgeniy Berdnikov via Exim-users <
> exim-users@???> wrote:
> > Yes, "References:" has 1018 octets while RFC limit is 998.
> > This is known bug for several Outlook versions.
> >
> > > Not sure how to mitigate this one. Maybe I should truncate/remove the
> > > header - and possibly break the thread?
> >
> > Better solution is to fold this header (split over multiple lines).
>
> How do I achieve that with exim-4.95? Config option??
There are several variants to try:
1. Use header add/remove directives in ACLs and/or routers to "reinstall"
problematic "References:" header if its length is too high, in hope
Exim would fold it correctly.
2. Use transport filters (ch.24) on delivery stage.
3. Route all incoming mails through external filter (such as Amavis),
it should reformat broken mails and re-inject them back.
I use variations of N3 with custom scripts, those configuraions are
complex and they can't be reduced to a single config option.
I have no experience with N1 and N2... Just try, it's interesting
are they working variants or not.
As ultimate solution, you can check for length of "References:" header
and remove it if length is too long. This variant should always work.
--
Eugene Berdnikov
