Re: loop homework, not an experiment, draft-crocker-email-deliveredto

On Sat, Aug 07, 2021 at 11:51:57PM +0100, Jeremy Harris wrote:
> On 07/08/2021 22:45, Viktor Dukhovni wrote:
> > Disclosing the addresses of (potentially Bcc'd) recipients to each other
> > feels rather like a bug that would need fixing.
> 
> Exim takes a toolkit approach. You're allowed to shoot yourself
> in the foot.  You're not forced to.

Perhaps so long as Exim administrators are duly warned in the relevant
docs, and multi-recipient Delivered-To is not enabled by default, and
the collective experience of the Exim user community is that this is
not in practice a problem, then so be it...

In Postfix, the philosophy is safety first, so you'll find guard rails
such as:

    https://github.com/vdukhovni/postfix/blob/master/postfix/src/pipe/pipe.c#L1146-L1170

which softfail multi-recipient deliveries to a transport that is
configured to add "Delivered-To:" and/or "X-Original-To" headers.

-- 
    Viktor.