MX Record Issue

[phn at icke-reklam.ipsec.nu]

John <ctcmptrdr at sbcglobal.net> wrote:
> Currently the company hosting our DNS has it configured something like the
> following (I can't do a zone xfer and I'm trying to get a copy of it. This
> may contain typos but I'm just attempting to show the records contained in
> DNS currently) -

> @    86400                IN    SOA       ns.company.com.
> root.company.com. (
>                                             3000
>                                             10800
>                                             604800
>                                             86400
>                                     )
>                                   IN    NS          ns.company.com.
>                                   IN    NS          ns2.company.com.
>                                   IN    NS          ns3.company.com.
>                                   IN    NS          ns4.company.com.

> mail.company.com.     IN    A            123.123.123.123
> www.company.com.   IN    A            234.234.234.234

> company.com.            IN        MX        10        mail.company.com.

> Our mail addresses are username at mail.company.com. I'm not sure why, it was
> setup before I arrived. This goes back years. We're now having a problem
> with a particular company where they cannot send email to us because there
> isn't an MX record for the 'sub-domain' mail.company.com. They are running
> an SMTP server from Tumbleweed.com, and they are using RDNS lookups to cut
> down on SPAM. Our Internet provider for some reason doesn't have any PTR's
> defined, I'm guessing because no one here asked them to. (I've only been
> here < 2 months).

> I've modified our mail server so that each user has an aliased email address
> of username at company.com. If that email address is used, then the company
> above doesn't have a problem. The error that they are getting from their
> tumbleweed software, which apparently started rejecting sending mail to us
> recently (~ 2wks ago), is that it can't find the MX record. I'm thinking
> that they changed something, but I've been told they haven't.

> So, to fix this on our end, I believe I need to have the DNS hosting company
> (despite protests from their support staff that it's definately not req'd)
> add another MX record something like this -

> mail.company.com.      IN        MX        10        mail.company.com.

Yes. And remind your dns-hostinmg company that it's not their task
to protest, they should do what you tell them ( if you are correct)



> And I need to contact our ISP, and have them add a PTR record for our mail
> server.
Should have been done long tiem ago. Every address you publish with
an 'A' record should have exactly one PTR record.

> I'm going to be adding a 2nd mail server in the next couple of months, so at
> that point, I'd have (2) more MX records and an additional A record added,
> with a lower priority pointing (100) to that server.
Correct

> Am I missing something obvious (outside of typo's that I may have made in
> the above example)? Is the additional MX record required?
Yes, it's what makes your service redundant ( as far as Internet delivery needs)

> Thanks.

> John




-- 
Peter Håkanson         
        IPSec  Sverige      ( At Gothenburg Riverside )
           Sorry about my e-mail address, but i'm trying to keep spam out,
	   remove "icke-reklam" if you feel for mailing me. Thanx.