MX and CNAME Problems

[etruitt]

Hello,
I am new to the whole DNS setup thing, so please bear with me.
Using H-sphere.

I have a client that has their own exchange server. They are connected via a dsl line with a dedicated IP. So I shut off mail on the "Edit Domain" screen and added an MX record that points to the ip address. Well come to find out that is wrong. Some mail gets through, but some gets bounced. I went to DNSreport.com to check the problem and they say

"You have one or more MX record(s) that contain an IP address. This is not valid. Some mail servers may be able to send you mail, others may not."

It also said that none of my mail server(s) seem to have reverse DNS (PTR) entries. Is this the CNAME? Right now they have none set up. I assume I need to add a mail.theirdomain.com up, but am not sure what to make the DATA field. Do I use my NS domain name? Does the TTL # stay the same? (defaulted to 86400)

What settings should I use if I want to have a client that doesn't use hsphere mail and just the web hosting?

Thanks for any help!
Etruitt

[Brangwyn]

What you need to do is create an "A" record that points to the IP address of your customers Exchange Server, call it "mail" for simplicity sake

mail.example.com 86400 IN A 111.111.111.1

Then create your MX record as

example.com IN MX 10 mail.example.com

The other dnsreport error should go away once these changes have propagated I believe.

[etruitt]

Thanks Brangwyn I will give it a try. Do you know, is this something that will work right away, or will it have to propogate through out the internet like other DNS records.

thanks again.
e.

[Brangwyn]

Unfortunately like everything DNS related it needs to propagate, maximum time for this to complete will be less than or equal to whatever the TTL is on your current "MX" record (TTL = Time to Live)

[etruitt]

Now it is complaining that there is no Refering DNS.

error: One or more of your mail server(s) have no reverse DNS (PTR) entries.
It is strongly urged that you have them, as many mailservers will not accept mail from mailservers with no reverse DNS entry.

What would fix this?

Thanks ahead of time.
e.

[Brangwyn]

Firstly you'll need to wait for propagation to finish I believe the error will go away once it has. If it still hasn't in 24-48 hours then post back.

[etruitt]

Well, I thought it was fixed, but I guess they are still getting blocked by some servers. The error they get is that there is an A=name mismatch.

So I did a look up on DNSreports.com and got this. Everything appears fine up til the last sentence. Is this the problem. Would that be something I could fix, or is that something US West needs to attend to?

Thanks for any help on this.

DNSreport.com message:

How I am searching:
Asking i.root-servers.net for 57.161.101.65.in-addr.arpa PTR record:
i.root-servers.net says to go to dill.arin.NET. (zone: 65.in-addr.arpa.)
Asking dill.arin.NET. for 57.161.101.65.in-addr.arpa PTR record:
dill.arin.net [192.35.51.32] says to go to NS3.MN.USWEST.NET. (zone: 101.65.in-addr.arpa.)
Asking NS3.MN.USWEST.NET. for 57.161.101.65.in-addr.arpa PTR record: Reports dnvr-apa-nas84-poolb57.dnvr.uswest.net. [from 204.147.80.1]

Answer:
65.101.161.57 PTR record: dnvr-apa-nas84-poolb57.dnvr.uswest.net. [TTL 86400s] [A=None] *ERROR* A record does not point back to original IP.

[Brangwyn]

I'd say they'd need to talk to US West about that and I'd suspect they're probably not going to do much about it.

Are you certain thats causing the problem? I know a few places check the PTR and like to see it exists, not sure if too many of them care though that it's not matching the A record.

[etruitt]

Just to follow up... Brangwyn was correct. USWest blew out the DNS info on thier end and it was not allowing a reverse lookup. It helps to really look at the reports at DNSreports.com and see whats going on with your domains.

Thanks again for the help.

[Brangwyn]

Yeah DNSReports is very handy, generally the first place I go when troubleshooting. Glad you got to the bottom of it anyway