SUMMARY: sendmail, no Internet DNS, sending Internet mail via mail gateway

From: Dale Shaw (
Date: Wed Mar 10 1999 - 19:15:06 CST

Hi all,

This problem has been fixed, thanks to the following people, especially
Rudy Willis who gave me the solution;

Alvaro Jose Fernandez Lago <>
Brian Exelbierd <>
Todd Herr <>
Larry Chin <>
Chad Price <>
Rudy Willis <>
David B. Harrington <>

Here is Rudy's response;



Have you compiled with NAMED_BIND=0 (see src/conf.h),
as per the README in src?

NAMED_BIND If non-zero, include DNS (name daemon) support, including
                MX support. The specs say you must use this if you run
                SMTP. You don't have to be running a name server daemon
                on your machine to need this -- any use of the DNS resolver,
                including remote access to another machine, requires this
                option. Defined by default in conf.h. Define it to zero
                ONLY on machines that do not use DNS in any way.

-- Rudy


This is the fix/hack/kludge..

Most others suggested I was the SMART_HOST (DS) feature of sendmail - I
mustn't have made it clear in my original e-mail that I was already
using this yet sendmail was still attempting name resolution on the
recipient's domain.

I'm not yet sure if anything will "break" with no DNS - even if some
features don't work, I doubt I would use them anyway. It's a very
simple configuration. Other suggestions did fix my problem in some
way, however most disabled any prospect of local delivery.

My original e-mail is below.

Thanks again, Dale

On Wed, Mar 10, 1999 at 03:16:07PM +1000, Dale Shaw wrote:
> Hi sun-managers,
> I am operating in a private network environment that makes use of an
> internal DNS server - There is no direct internet connectivity from the
> machines I work on, however there are mail and proxy servers
> available.
> I am using sendmail 8.9.3 after giving up on the Sun distribution.
> All I want to be able to do is send mail from my system(s) to addresses
> on the Internet via a local mail gateway. Despite a fair amount of
> reading and hair pulling, sendmail still appears to want to resolve the
> recipient address before firing it off to the mail relay.
> The sendmail FAQ solution to this problem is to disable DNS altogether
> by removing 'dns' from nsswitch.conf, this won't work for us since we
> need the use of the internal DNS.
> I've tried various things, including making use of the
> "confSERVICE_SWITCH_FILE" define pointing to /etc/nsswitch.files,
> forcing sendmail to chroot() before writing files (this however did not
> work how I thought it would, still reading /etc/resolv.conf instead of
> the resolv.conf in the chroot jail.
> Infact I've tried so many things I've forgotten most of it :-)
> So, the big question is, is there a way to have sendmail deliver all
> non-local mail to the specified (DS) even when it can't resolve the
> recipient's address? Sendmail happily accepts mail destined for
> addresses in the same domain as the machine I'm sending from.
> To clarify:
> My boxes don't have access to a "full" DNS; The mail server I
> want to deliver mail though does; Sendmail sits there trying to
> resolve names, then fails; I want it to blindly deliver any
> non-local mail to the said gateway.
> Hope I'm making sense!
> cheers, Dale.

Dale Shaw                :   ,-----.                              :  :  :  (`  | e l e c t   A p p r o a c h  :
Systems Guy              :  |  _)  :----------------------------  :
Ph (02) 6241 5633   ::::::  `------'  :::

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