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I have server with a mail service running at domain o1.danilocarneiro.com. I use Cloudflare as DNS, so I have configured an A record on cloud flare to 152.67.52.238. This is actually the IP of the server.

The problem is because while running mail-tester.com check it warns about Reverse DNS and recommends to add PTR record. My first question is where should I add this record, I guess it's in Cloudflare but I'm really not an expert on DNS and network subjects.

Cloudflare PTR Record screenshot

I'd like to know how to create this record, I have tried a record with: Name: o1.danilocarneiro.com. Domain name: 238.52.67.152-in-addr-arpa. It doesn't work.

I also tried. Name: 152.67.52.238. Domain name: o1.danilocarneiro.com. It also doesn't work. Mail-teser and other checkers like mxtoolbox.com keeps saying PTR record not found.

Could anyone please explain to me or demonstrate how to create a valid PTR record for my mail server (o1.danilocarneiro.com -> 152.67.52.238)

Thank you so much!

Jim
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mafaltti
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1 Answers1

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At Cloudflare in your DNS zone for danilocarneiro.com

Go to create a PTR record as following:

Type Name        Domain Name               TTL

PTR  o1   238.52.67.152.in-addr.arpa  auto(suggested)

By doing this you should see.

; <<>> DiG 9.10.6 <<>> PTR 238.52.67.152.in-addr.arpa
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62521
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;238.52.67.152.in-addr.arpa IN  PTR

;; ANSWER SECTION:
238.52.67.152.in-addr.arpa 85728 IN PTR o1.danilocarneiro.com.

;; Query time: 29 msec
;; SERVER: XXX.XXX.XXX.XXX#53(XXX.XXX.XXX.XXX)
;; WHEN: Tue Aug 25 10:11:51 2020
;; MSG SIZE  rcvd: 90

You should also note this CloudFlare Article - PTR

Remember allow up yo 72 hrs in order for dns to propagate, but with cloudflare can be almost instantly.

Santiago
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  • from https://support.cloudflare.com/hc/en-us/articles/360019093151-How-do-I-add-a-PTR-record-to-CloudFlare- seems like they don't allow this. Did you manage to get it working? – E_K Mar 11 '21 at 11:53
  • Please note that this record should be in your domain name server (DNS) in order to resolve your domain. But actually, it isn't the right way where you should start to update your PTR record. I mean, you must have it there. But, for IP's you must contact your IP Provider in order to them add the PTR record as your needs, then go to cloudflare and do the same. As they manage the IP and also the records for that IP. – Santiago Mar 12 '21 at 12:50
  • "Remember allow up yo 72 hrs in order for dns to propagate" There is no DNS propagation, this is a myth. If you add a completely new record, you have, at worst, to wait the "negative TTL" value of the zone it appears in, if you query recursive nameservers, but if you query authoritative nameservers the record will be there "immediately". – Patrick Mevzek May 27 '22 at 20:03
  • For sure, always if you query the authoritative server it will have the most updated record, because of it's authority. Whatever it answers thats it. Most internet dns cache servers don't query authoritative servers inmediatly. – Santiago May 29 '22 at 02:59