Specialist check
PTR and rDNS checker for cold email
Check whether a custom SMTP or dedicated sending IP has reverse DNS that points to a hostname and resolves back to the same IP.
- Checks
- Resolves IP to PTR hostname and hostname to IP, then checks whether both directions agree.
- Cannot tell
- It cannot inspect SMTP HELO, the sending service, or private egress configuration.
Expected time: about 5 to 20 seconds. Some public services can take longer.
Source: Live Google Public DNS in both reverse and forward directions.
Questions
It checks the reverse DNS hostname for an IPv4 address, then confirms whether that hostname resolves back to the same IP.
Enter the outbound SMTP egress IPv4 address used by your custom SMTP server or dedicated sending provider. You can also enter a hostname, and the checker will use its first IPv4 answer.
Forward-confirmed rDNS shows that the reverse hostname and forward DNS agree. For custom SMTP paths, mismatched or missing rDNS is a visible infrastructure risk.
No. PTR/rDNS is only one SMTP egress identity check. A launch signoff still needs SPF, DKIM, DMARC, blacklist status, tracking-domain checks, inbox setup, and receiver requirements.
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