A PTR record maps a sending IP address back to a hostname. Mailbox providers check that the PTR resolves and that the hostname's A record points back to the same IP (forward-confirmed reverse DNS).
Can I set PTR records in my own DNS?
No. PTRs live in the IP owner's reverse zone. Your hosting provider or ESP sets them, though some offer self-service.
Why does reverse DNS (PTR) records matter for deliverability?
Gmail's sender guidelines require valid forward and reverse DNS. Missing or generic PTRs are a classic spam signal and cause outright rejections at many gateways.
What is the first step to get started with reverse DNS (PTR) records?
Ask your hosting or ESP provider to set a PTR for each sending IP.
What is the most common reverse DNS (PTR) records mistake?
Generic PTRs like 203-0-113-10.provider.net.