Blog
Why Your PTR Record Is Killing Your Email Delivery
SPF and DKIM can pass — and mail still gets deferred or spam-foldered because the connecting IP has no PTR or a generic hostname. Many receivers treat that as sloppy or hostile.
What breaks
Self-hosted Postfix on a VPS: you need PTR pointing to mail.example.com and an A record back. Cloud IPs without PTR are a common “everything worked in Mailgun” moment when you migrate.
See PTR and self-hosted email.
Fix path
Open a ticket with whoever owns the IP (AWS, Hetzner, etc.). Set PTR to your mail hostname. Wait for propagation — then verify FCrDNS.
dig +short -x YOUR.SENDING.IP
Check PTR + blocklists
DNS Preflight →FAQ
What is PTR?
Reverse DNS: IP resolves to a hostname — filters expect it to match your sending identity.
Who sets PTR?
Usually your hosting provider or ISP for the IP — not your domain registrar’s DNS.
Does SaaS mail need PTR?
The ESP’s IPs are already configured — self-hosted and dedicated IPs need PTR most.
What is FCrDNS?
Forward-confirmed reverse DNS: PTR hostname resolves back to the same IP.
How do I test?
DNS Preflight checks PTR path; dig -x for the IP from your laptop.