Re: Sendmail config problems (mail to remote hosts bouncing)

[Brian Candler <B.Candler at pobox.com>]

On Wed, Dec 04, 2002 at 06:12:36PM +0300, Luke Kyohere wrote:
> Hello, I am having a problem sending mail to a host
> machine host.someplace.com. where someplace.com is not my domain:
> 
> eg Mailto: user at host.someplace.com
> 
> Somehow my MTA (sendmail) cannot seem to resolve the host
> machine and it returns an error:
> 
> Name service error for host.someplace.com
> 
> and yet mail for user at someplace.com has no problem being sent.

Try querying the DNS yourself: sendmail would try to look for an MX record
followed by an A record, so you can do:

$ nslookup -q=mx host.someplace.com.
$ nslookup -q=a host.someplace.com.

If you get DNS errors back, then it's a DNS problem at someplace.com

> I would have expected that my MTA would forward the mail to someplace.com
> which would then send it to host.someplace.com. This way my machine does
> not need to know about all the hosts at every domain. (I would have
> thought).

No. It doesn't know the difference. If you try to mail to user at any.where,
sendmail will first try to find MX records for 'any.where', and will use
them if they exist. If not, as a fallback it will try to find A records for
'any.where'. If not, it should bounce.

Regards,

Brian.

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