Re: [exim] Infinite Loop With 'no such address'

On 1/31/06, Marc Sherman <msherman@???> wrote:
> Burhan Khalid wrote:
> >
> > I already had a feeling these were the only two options. I guess I'll
> > have to have a word with the client since the IP is shared against an
> > entire office.
>
> It sounds like you might be having this problem with an MUA submission,
> and you're responding to the bogus address with a 5xx failure in the
> RCPT acl. Generally speaking, MUAs can not be trusted to handle 4xx or
> 5xx failures correctly, leading to things like infinite retries from the
> MUA outbox. For this reason, it's usually preferred to accept and
> bounce in local submission mode. Just make sure you've got a confirmed
> envelope-from address to send a bounce to before accepting the message.
> A good way to do that is to require authenticated submission, and use
> control=submission to have exim rewrite the envelope-from address to
> $authenticated_id@$qualify_domain.

Marc:

I only half-understood your suggestion. I understood the part that
we can't trust client software to handle errors correctly. I already
require authenticated submission (users must authenticate before they
can send -- is this the same thing?). I don't understand the last
part, can you please dumb it down a bit? How can I tell exim to send a
bounce back message?

Thanks,
Burhan