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

> >> When mail systems do internal forwards using things like .forward or
> >> /etc/alias, each forward adds a Delivered-To, which breaks a->b->c->a
> >> loops.  Since there's no SMTP involved, there's usually no Received and
> >> never an Envelope-To.  Also, as Sam, Viktor, and I have explained, the
> >> internal forwards are not necessarily to or from anything that has an
> >> externally valid envelope address.
> >
> > What happens when there are multiple recipients? Message splitting?

> For Delivered-To loop breaking it doesn't matter since it's just a token
> to show that the message has already been wherever it is.

Not quite getting it.

A single token describes all of the recipients? Or do you simply generate more
than one Delivered-to: in the same message?

Let's make this concrete. We have these aliases:

alias1: local-recipient-1, local-recipient-2

alias2: remote-recipient-1, remote-recipient-2

How many message copies do these generate, and what fields are added?

And while we're at it, what does

alias3: alias3, extra-recipient-1

do?

> I believe that Exim does one delivery at a time so its Envelope-To only
> has one address.  I can ask Jeremy what happens with multiple recipient
> messages.

Yes, please do.

				Ned