Glossary

PTR Record — Reverse DNS for Email Delivery

A PTR record (pointer record) maps an IP address back to a hostname — the reverse of an A record. For email delivery, PTR records are critical: many receiving mail servers perform a reverse DNS lookup on the sending IP and reject email if no PTR record exists or if the PTR hostname does not forward-resolve back to the same IP.

Why PTR Records Matter for Email

Without a PTR record, major mail servers including Gmail, Outlook, and Yahoo may reject your email outright. A missing PTR record is one of the most common causes of email landing in spam or being rejected at the SMTP level.

Forward-Confirmed Reverse DNS (FCrDNS)

A valid PTR record requires forward confirmation:

1. IP 192.0.2.1 → PTR → mail.example.com
2. mail.example.com → A → 192.0.2.1

Both must match. If the PTR hostname resolves to a different IP, receivers may still reject.

How to Add a PTR Record

PTR records are set by your hosting provider or ISP — not in your domain's DNS. Contact Hetzner, DigitalOcean, AWS, or your VPS provider's control panel to set reverse DNS for your IP.