Question about MX record.

[Jim Reid]

>>>>> "HeePok" == HeePok Lee <wind at bora.net> writes:

    HeePok> Hi all!  I set the domain name on my DNS like below.

    HeePok> mediacity.co.kr.  IN MX 10 mail.mediacity.co.kr.
    HeePok> mediacity.co.kr.  IN A 210.105.60.68
    HeePoK>   IN MX 90 mediacity.co.kr.
    HeePok> mail IN A 164.124.107.29 

    HeePok> Mail server is running on both servers(210.105.60.68 and
    HeePok> 164.124.107.29).  By the way, when I send a mail to
    HeePok> ID at mediacity.co.kr, sometimes mail is lost.  To where mail
    HeePok> is going?  Could you explain why mail is lost?

This will probably be a mail problem. Check the mail logs on your
servers and the configuration of your mail system. You first need to
establish that the mail is being delivered to your mail system(s).
Once it gets there, you'll need to trace its path through the mail
system to find out why the messages disappear. Maybe they're stuck in
a queue or have incorrect headers or the mailboxes are mangled, etc,
etc.

I've just looked up mediacity.co.kr in the DNS. The zone has one MX
record:
	mediacity.co.kr.        12H IN MX       10 ns.kobis.net.

Are you running split DNS? ie Do you have two versions of this domain,
one for the Internet and one for internal use? If you're not using
split DNS, then there's a serious discrepancy between what you've
quoted in your mail and what actually is in the DNS for this zone.
The information that's in the DNS right now says that mail for
mediacity.co.kr will be delivered to ns.kobis.net and not the mail
servers listed in the zone file entries you provided. It could be that
mail for mediacity.co.kr is being sent to the wrong mail server
because the DNS for this domain doesn't seem to be set up the way you
think.