Re: [Exim] strange failure to lookup IP address

On Wed, 30 Jul 2003, Philip Hazel wrote:

> On Tue, 29 Jul 2003, Tom Davidson wrote:
>
> > Unfortuantely I'm still getting the same problem having removed
resolv.conf!
>
> Well, I wouldn't expect any DNS resolution to work if you have removed
> resolv.conf. At least on the systems I'm familiar with.
>
> However, let's consider your debug output. It successfully routes the
> original address:
> [snip]

That's what I'd surmised.
And yes, IP's obtained from hosts file.

> > getting address for mailrelay1
> > DNS lookup of mailrelay1 (A) gave TRY_AGAIN
>
> It looks in the DNS and fails (because there's no resolv.conf). I
> presume you don't *want* to look in the DNS. Try setting
>
> gethostbyname = TRUE
>
> on the smtp transport where fallback_hosts is set.

Yep, don't want DNS lookups.
I had tried setting "byname" on the fallback_hosts setting:
fallback_hosts = mailrelay1:mailrelay2:mailrelay3:mailrelay4 byname
but I've just realised in re-reading the docs that this is probably wrong as
that is a setting for manualroute.

Will try that next time, thanks.

There's one thing I'm a bit unclear about:
Why does exim's default behaviour seem to be to do a DNS lookup rather than
obey the OS lookup settings (eg. the hosts setting in /etc/nsswitch.conf on
Solaris)? Is this because most installations of Exim will be talking
directly to the Internet and so can use MX records? Still would have
thought it would use the OS settings, but could be forced otherwise...
(Or have I misunderstood things?)

Tom