Reverse DNS is not a valid Hostname

Hi, i need help with that, i have a error on testing on or other similar testers.

The error is: B Reverse DNS is not a valid Hostname [/B]

now i have this config: A 43200 A 43200 A 43200 A 43200 A 43200 CNAME 43200 CNAME 43200 NS 43200 NS 43200 MX 10 43200 PTR 43200 SOA 7200 300 1209600 10800 N/A TXT v=DKIM1; k=rsa; t=y; p=2 qYq SMa HTg DVR qRG JQj jtO lFw 9b/ …; 43200 TXT v=DKIM1; k=rsa; t=y; 43200 TXT v=DMARC1; p=none 43200 SPF v=spf1 a mx ip4: ~all 43200 AAAA 2001:89tf:3:1e9f:: 43200 AAAA 2001:89tf:3:1e9f::

AND my Mail Server Hostname (FQDN):

How i need configure the dns? or how to fix that?

Hi dino

Welcome to IW forums

How you correct RDNS depends upon if you are delegated full control over your IP cidr/IP or not

If you have full delegated control (usually not for small cidr), you can set the PTR record in your DNS settings for domain.url

If you are not delegated control, you need to ask your IP address provider to set your RDNS as you need it

Many thanks


how can I know if i have full delegated control or not?
ok, and how it should be configured ?

somthing like this: PTR 43200
or PTR 43200

or PTR 43200 PTR 43200

can you put an example please.

Hi Dino
I do not believe you have been delegated full control, your first post shows PTR but you have obscured the resolve/test, so can only go by guessing, and if you are not sure over PTR settings, then it points to no delegated control.
Delegated control are usually assigned to a /24 or /16 block, may have changed now, but it can be provider choice to delegate or not.
In any event, here is a PTR/RDNS for 1 of our IP PTR IN 7200 107ms
I would suggest you contact your IP address provider (network provider) and ask them to set the RDNS for you. Once they confirm set, wait a few hours and test, and it should show RDNS, but please make sure you request the correct FQDN to use for RDNS, which usually matches your mail server smtp greeting.
Many thanks

Thank you, your example helped me.
I entered my ip provider’s web site there i could set up what you said.

Reverse DNS is IP address mapping of a domain. Basically this has to be informed to your internet IP provider to point the IP to your domain.