Re: [exim] Callouts, NULL DSN

On Mon, 2005-08-22 at 09:34 +0100, Jeremy Harris wrote:
> So, I'm confused. Surely the avoidance of loops always requires
> callout to use a null sender, and postmaster and header-sender
> callouts are in contravention of that? I'd say that the warning is
> *always* appropriate. Your "doesn't trigger callouts of its own" is
> not under your control; it's the remote end which might be deciding to
> make yet another callout.

I mean an address like 'postmaster-nocallout@???' which,
if you received a probe for that address, would not cause _further_
callouts.

To do a header_sender callout with a null sender is broken, as Steve B
discovered. The RFC2822 sender address may never be used as an RFC2821
sender, and may reject all bounces.

--
dwmw2