Reverse DNS (PTR) Records and Email
Why Reverse DNS is critical for sending servers and how to verify your PTR records match your hostname.
What is a PTR Record?
A PTR record maps an IP address to a domain name (the opposite of an A record). It is used for Reverse DNS lookups. For example, looking up IP 8.8.8.8 might return dns.google.
Why it Matters
Many major email providers (Gmail, Yahoo) will automatically reject or flag emails from servers that do not have a valid PTR record. It is a vital check used by spam filters to verify that the sending IP is tied to a legitimate domain.
Troubleshooting PTR
If you are running your own mail server (postfix, exim), you usually need to ask your ISP or Virtual Private Server (VPS) provider to set the PTR record for you. Most control panels (AWS, DigitalOcean) provide a simple UI for this.
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