Bug#271564: Fwd: Mail delivery failed: returning message to sender

[Andreas Metzler]

On 2004-09-15 Mike Mestnik <cheako911@yahoo.com> wrote:
[...]
> > cheako@filbert.is-a-geek.org
> R: dnslookup_relay_to_domains for cheako@filbert.is-a-geek.org
> cheako@filbert.is-a-geek.org is undeliverable:
>   Unrouteable address

> Here is what I get from DNS...
> train:~# host -t MX filbert.is-a-geek.org
> Host filbert.is-a-geek.org not found: 3(NXDOMAIN)
> train:~# host filbert.is-a-geek.org
> filbert.is-a-geek.org has address 10.0.0.20
[...]

Hello,
10.0.0.0/8 is private address-space and exim is configured to ignore
it by default, these quotes from #270748 should explain why:

| It does so to avoid delivering e-mail to misconfigured domains to the
| wrong place.

and

| To elaborate a little bit more: This is also very useful for working
| sender verification. - It is a rather common way to disable e-mail
| delivery for domains by having an A-record pointing to private address
| space. If ignore_target_host is not set exim will happily accept mail
| with 'mail from: x@thisbrokendomain' but a bounce-message (if one was
| generated) could not be delivered (no root to host) and would be
| frozen, stuck in the queue. 

Remove 10.0.0.0/8 from ignore_target_hosts and you are set.
              cu andreas
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