The three values
For a clean mail server, PTR record, A record and HELO name must agree:
The first two lines together constitute FCrDNS (forward-confirmed reverse DNS). Only the return path from name to IP makes the PTR record dependable — because the PTR alone could be set to any name by any IP owner.
Step 1 — Create the PTR record
The PTR record does not live in your own DNS zone. It belongs in the reverse zone of the IP block, which is managed by the owner of the IP — your hosting provider. With most providers you find the setting in the customer panel under IP or server management, often labelled "Reverse DNS" or "PTR".
Enter the fully qualified hostname your mail server should carry. Choose a meaningful name such as mail.yourdomain.com — not the provider default like vps12345.hoster.com. Generic names of that kind are read by filters as a pattern for dynamic or unattended systems.
Step 2 — Add the A record
In your own zone you create the matching forward entry:
It must point at exactly the same IP the PTR record refers to. Only then is FCrDNS satisfied.
Step 3 — Align the HELO name
The mail server must introduce itself with the same name. In Postfix:
In Exim it is primary_hostname; other systems have their equivalent. What matters is exact agreement with the PTR record.
Don't forget IPv6
If your server also sends over IPv6, everything above applies to the IPv6 address as well. Google rejects mail from IPv6 addresses without a PTR record as a matter of policy — one of the strictest rules there is. If you cannot configure IPv6 cleanly, explicitly restrict outbound sending to IPv4 rather than doing it halfway.
Common mistakes
- PTR created in your own zone. Ineffective — it has to be set by the IP owner.
- A record missing or pointing elsewhere. The PTR exists but FCrDNS still fails.
- HELO diverges. The server announces its internal hostname instead of the public FQDN.
- Multiple outbound IPs — each needs its own PTR record.
- Keeping the provider default name. Technically correct, but filters score the pattern negatively.
Testing
After the change it takes anywhere from minutes to hours depending on the provider. Then send an email to hello@analyzemy.email: the report shows the PTR record, FCrDNS status, HELO match and the ASN assignment of your sending IP.