Problems with DNS Manager


A little history:

I outsourced my email because of email delivery problems. I couldn't figure out the correct DNS settings so that my mail wouldn't be rejected/marked as spam on account of no reverse DNS.

The problem:

1. I have 2 domains: and

2. I send mail through both.

3. I have rDNS through Linode pointing both of my IP addresses to

4. When I send mail through, the reverse DNS will not work because of the 2 IPs I have are already on (I'm assuming) and will sometimes be rejected because of it.

My question:

How do I set it up so that:

1. I can send mail from both AND and the rDNS will pass without having a dedicated rDNS IP per domain I want to send mail through?

Currently, I have my MX entries as and and SPF pointing to them also but I no longer wish to use their services. I want to host my own (and have done so in the past) but my DNS woes are the main problem.

THEY can figure out how to set things up so I'm sure there's a way to do it with my own setup?


Eternally Frustrated

3 Replies


I couldn't figure out the correct DNS settings so that my mail wouldn't be rejected/marked as spam on account of no reverse DNS.
How about starting with making sure you have your rDNS set. You do so by clicking on the "Reverse DNS" link off the "Network" tab for the appropriate linode. Make sure you have a valid A record for the IP you are wanting it set to before proceeding or you'll have to wait for the DNS cache to expire before it will accept it. See ~~[" target="_blank">]( … de-manager">]( towards the bottom.

Also your real domain name(s)/IP would be beneficial in diagnosing your problems.


> How about starting with making sure you have your rDNS set.

The rDNS has been set in Linode's control panel for well over a year now.

I understand that it would make things much easier if I told you my domains. I don't include my domain(s) because:

1. Privacy - I don't feel comfortable airing my ignorance AND telling everybody where to exploit it.

2. My MX and SPF records are currently pointing off-site so nothing in there would be of any help.

I've read every bind/DNS article I could find and they still don't answer a basic question. What's worse, I'm too daft to figure out something that's apparently obvious to everybody else.


1. I have and

2. I have 2 zone files and
> 14400 IN MX 10 IN TXT "v=spf1 ip4:64.22.NNN.NNN ip4:64.22.NNN.NNN ~all"
> 14400 IN MX 10 IN TXT "v=spf1 ip4: ip4: ~all"

When I use mxtoolbox for, it says that there's a problem because there's no reverse DNS entry for that domain.

Of course not, because both rDNS are pointing to

But I know that there's got to be a way for bind to be configured in a way that will allow me to send through both domains without having a dedicated IP for each domain! Right?

I tried using something like (in DNS manager):

> 14400 IN MX 10 IN TXT "v=spf1 mx -all"
> 14400 IN MX 10 IN TXT "v=spf1 mx -all"

But when I clicked the "Check" button (assuming it's named-checkconf? It told me:

zone '' (out of zone) is a CNAME (illegal)

Yet there are no CNAMEs!

Believe me, These forums aren't my first line of support. I try as hard as possible to solve the issues I have on my own before coming here. With that said, any (real) help would be appreciated!


I've figured everything out on my own (finally).

In case anybody else is ever confused as I am, here's what your bind files should look like (pertaining to MX and SPF entries):


# Of course, youll always need your zone entries
# 64.22.NNN.NNN
zone "" { type master; file "/etc/bind/"; allow-query { any; }; };

# 64.22.NNN.NNN
zone "" { type master; file "/etc/bind/"; allow-query { any; }; }; (ALL mail will be sent through this domain)

mail                IN  A   64.22.NNN.NNN        IN  MX  10        IN  TXT "v=spf1 mx -all"    14400   IN  MX  10        IN  TXT "v=spf1 mx -all"

I'm not sure if the include directive in SPF is necessary but if it doesn't hurt anything, I ain't changing it.

Anyway, the main problem I was having is that I was trying to create 2 mail servers; one for and one for .. emails from would always fail rDNS because rDNS was always set to for both IPs.

Once I figured out that I only needed ONE mail server and could tell that server to allow to send mail through it, things worked out fine. Getting that through my thick head was the problem.

ALSO! When I was toying with Linode's DNS Manager, it was confusing because the MX entry form separates the domain from the subdomain .. So instead of typing into the domain part, you have to type in the domain part and type mail in the subdomain part of the form. If you don't, you'll get a strange error when you "Check" it.


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