PTR record (reverse DNS)
Also called: Reverse DNS, rDNS, PTR
A PTR record maps an IP address back to a hostname: the reverse of a normal DNS lookup. Mail servers use it to check that a sending IP belongs to a properly run mail server.
Gmail requires valid forward and reverse DNS for sending IPs: the IP’s PTR record must name a hostname, and that hostname must resolve back to the same IP (Google). Yahoo asks for non-generic PTR records that reflect your domain and don’t look dynamically assigned (Yahoo).
How it affects cold email
PTR records belong to whoever runs the sending IP. If you send through Google Workspace, Microsoft 365 or another hosted provider, they manage it for you. It only becomes your job if you run your own mail server.
How Inboxed handles it
- Inboxed sends through your mailbox provider’s servers, so their IPs and PTR records are used. Inboxed doesn’t run sending IPs of its own for campaigns.
Related terms
Sources
Sources checked on 8 November 2026. Rules change, so check the source before you rely on a detail.
- Email sender guidelines · Google, Gmail Help
- Sender Best Practices · Yahoo Sender Hub
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