0

I have a dedicated server (Ubuntu 18.04 with virtualmin & webmin) which is hosting 7 WordPress sites on it. I have set up MX, DMARC, SPF and DKIM records for each one of them but dns tests online kept mentioning that I need to set up PTR records for reverse DNS too if I want to send/receive emails. (The other records passed successfully).

On googling about PTR records, I understood that I need to request my host to provide me with an ipv6 address which he did and gave me a link to set it up.

The link took me to a page with a single input field, a submit button and a one-line explanation that says:

Edit reverse DNS entry for XXXX:feXX:XXX:XaX::fXe:fXXd

What exactly should I add and submit here? The reverse IP address of my server followed by .in-addr.arpa or something else? And what should I add in my domain registrar's record after?

3

A PTR record contains the hostname corresponding to the given IP address. Therefore you enter in your fully qualified domain name. You must also append a dot to it, though your provider's control panel might do this for you.

So it should look something like:

myhost.example.com.
7
  • Will all the virtual servers (sites) be able to use that one ptr record or do I need a separate ipv6 address for each site? Also, in my domain registrar records, I must add a AAA record that points the ipv6 address to the site domain or? – AndrewL64 Jun 14 '20 at 23:33
  • @AndrewL64 I thought this was about sending email? Why do you mention web sites? And also you need to set a PTR record for your IPv4 address as well. – Michael Hampton Jun 14 '20 at 23:35
  • My apologies for the confusion. I have been hosting these sites for a while but have never really deal with the email records so I'm a bit green with this. So a common global PTR record will work for all sites as opposed to for example, DKIM records which I have to individually set-up for each site? And from what I gathered online, I thought PTR records only work with ipv6? So I can send mail with just an ipv4 address with a ptr record set-up on it? – AndrewL64 Jun 14 '20 at 23:40
  • 2
    @AndrewL64 Consider Microsoft 365. When somebody sends an email through them, the server is identified as a microsoft.com (outlook.com, etc) server, not named for whatever domain the email sender has. Similarly, your server will identify itself with your domain name rather than your customers' domain names. As for PTR records, they are for both IPv4 and IPv6. You'll need both to ensure email delivery to everywhere on the Internet is not refused for the lack of such a record. – Michael Hampton Jun 15 '20 at 0:02
  • Oh ok. That clears up a lot of the confusion I had. But with regards to ipv4, how do I set up a ptr record for that? And where does .in-addr.arpa come into play in all this since I keep seeing it online when googling about reverse dns? – AndrewL64 Jun 15 '20 at 0:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.