nt-scomau
REVERSE DNS (PTR) PROBLEMS EXIST
Cloudflare not generating dc-#### subdomain for email
I have removed the site from Cloudflare and added again hoping that it will generate a dc-### subdomain for the PTR issue for email deliverability goes away however the issue is still there.
DNS records
Cloudflare returns _dc-mx hostnames for MX records when the name to which the MX record points is proxied. This automatically un-proxies the records so mail can be delivered. This is nothing to do with PTR records.
Assuming I have the correct domain, this is happening for you…
https://cf.sjr.org.uk/tools/check?d4693afbdb154c35898df6e8a4796320#dns-mail
Setting your mail subdomain to “DNS only” will stop the _dc-mx being returned.
If you need to set a PTR record, that needs to be set through whoever owns the IP address your mail server is sending from.
Thank you so much for your help.
Actually we use nt-s.com.au for email addresses. We do not use mail.nt-s.com.au
When the A Record of nt-s.com.au is set to DNS only, I do not see PTR issue in my cPanel. The PTR issue comes back as soon as I proxy the A record.
I do want to proxy through cloudflare for this domain. The MX record is indeed set to DNS only.
The cPanel error is as below:
> #### REVERSE DNS (PTR) PROBLEMS EXIST
*> *
> The system sends the domain “nt-s.com.au” in the SMTP handshake for this domain’s email. “nt-s.com.au” resolves to “172.67.170.179” and “104.21.71.147”, not “103.64.149.18”.
*> *
> To fix this problem, contact your system administrator and request that they create a DNS “A” record for “nt-s.com.au” whose value is “103.64.149.18”.
However I already have A record for “nt-s.com.au” whose value is “103.64.149.18”.
The MX records itself will always be 
DNS Only. The hostname contained in the MX records also needs to be DNS Only or you will see the _dc-mx hostname returned. These _dc-mx hostnames will always result in email problems. It is important that the hostname present in an MX record is always DNS Only.
That record is set to 
proxied, which means that it will not return the address you have set. It will instead return Cloudflare proxy IPs, like so:
% dig a nt-s.com.au +short
104.21.71.147
172.67.170.179
Your best option, if your server supports it, is to configure your mail server to use the mail hostname in its EHLO and keep that record DNS Only so that its real IP is published. Any PTR record for that IP will need to be set by Relentless Hosting.
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