The use of Reverse DNS (PTR) checks is a historical means of checking that the message being delivered is not SPAM. If you are having email delivery issues, this is most likely not the reason. It's more likely that your SPF DKIM DMARC records contain errors.
The following is a more detailed explanation as to why this is treated as a false positive.
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PTR is correct, but doesn’t match cPanel’s expectation
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cPanel expects the PTR to exactly match the server’s configured hostname or the specific domain you’re checking.
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Many hosting providers set the PTR to a generic rDNS name (like
server123.hostingprovider.com). This is valid and accepted by mail providers, but cPanel flags it because it doesn’t match your domain.
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Multiple domains sending mail from the same IP
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A single IP can only have one PTR record.
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If you have multiple domains (e.g.,
example.com,example.net) sending from that IP, only one of them can “match” the PTR. The others will always show a warning in the module, even though mail will still deliver fine if SPF, DKIM, and DMARC are correct.
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cPanel’s module checks forward-confirmed reverse DNS (FCrDNS) strictly
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Some mail providers only require that:
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The PTR exists.
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The hostname it resolves to has an A record pointing back to the same IP.
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If that condition is met, big providers like Gmail and Outlook are happy — but cPanel still says “problem” if it doesn’t perfectly line up with the domain you’re inspecting.
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