"Steven Klass" <[EMAIL PROTECTED]> wrote:
>
>Please help me out on this one, what is an MX record.. I thought you might
>lead me to this, would you mind explaining this a little bit or pointing me
>to the faq.
It's a nameserver record that points to the mail exchanger for a given
domain. RFC 974 (see
http://Web.InfoAve.Net/~dsill/lwq.html#more-information) has the
details.
Basically, when host A sends a message to host B, it looks in the DNS
for an MX record pointing to host B's mail exchanger. If it doesn't
find one, it tries to send directly to host B.
Here's how you can look up a host's MX:
de5@sws5$ nslookup
Default Server: x10ns.ens.ornl.gov
Address: 128.219.200.249
> set type=mx
> speedchoice.com
Server: x10ns.ens.ornl.gov
Address: 128.219.200.249
Non-authoritative answer:
speedchoice.com preference = 10, mail exchanger = mail01.detroit.speedchoice.com
speedchoice.com preference = 10, mail exchanger = mail.phoenix.speedchoice.com
Authoritative answers can be found from:
speedchoice.com nameserver = ns1.detroit.speedchoice.com
speedchoice.com nameserver = ns2.detroit.speedchoice.com
mail01.detroit.speedchoice.com internet address = 24.221.95.31
mail.phoenix.speedchoice.com internet address = 24.221.30.31
ns1.detroit.speedchoice.com internet address = 207.238.183.71
ns2.detroit.speedchoice.com internet address = 24.221.95.3
>
This says that a message addressed to [EMAIL PROTECTED] should be
sent to either mail01.detroit.speedchoice.com or
mail.phoenix.speedchoice.com. Since they both have the same preference
(10), either can be used.
Your system could be configured as an SMTP server, but if it has an MX
record pointing elsewhere, no remote systems will ever try to send it
mail, it'll go to the host identified in the MX record.
-Dave
