PTR Record Look Up (Reverse DNS)
Related tools
What this is
A PTR record maps an IP address back to a hostname — the reverse of an A record. Mail servers check it constantly: sending mail from an IP with missing or mismatched reverse DNS is a strong spam signal.
How to read your result
For a mail server IP, the PTR should exist and should match the name the server uses in its SMTP greeting (and that name's A record should point back at the same IP — "forward-confirmed reverse DNS").
Common problems and how to fix them
No PTR record on a sending mail server IP
How it shows up: Outgoing mail is rejected or lands in spam at major providers; bounce messages mention reverse DNS or rDNS.
How to fix it: PTR records are controlled by whoever owns the IP block — your hosting/cloud provider — not by your domain's DNS. Set it in the provider's console (most clouds have an rDNS field) or open a ticket, pointing it at your mail server's hostname.
PTR exists but does not match the mail server's HELO name
How it shows up: Stricter receivers defer or reject mail; spam scores are elevated despite SPF/DKIM passing.
How to fix it: Align all three: the PTR name, the hostname the mail server announces (HELO/EHLO), and that hostname's A record. All should agree on one name and one IP.
Generic provider PTR (e.g. 203-0-113-7.provider.example)
How it shows up: Some receivers treat mail from generic-looking rDNS as consumer-grade and score it as likely spam.
How to fix it: Replace the default PTR with a hostname under your own domain (e.g. mail.yourdomain.com) via your provider's rDNS settings.
Related reading
- PTR Records and Reverse DNS: What They Are and Why Your Mail Depends on ThemHow reverse DNS and PTR records work across IPv4 and IPv6, who actually controls them, and why mail servers use FCrDNS to decide whether to trust your IP.
- DNS Record Types, ExplainedA practical tour of every DNS record you will actually touch — A, AAAA, CNAME, MX, TXT, SRV, CAA, the DNSSEC set and the modern HTTPS record — with syntax, gotchas and when to reach for each.
- Who Owns This IP? Reading ASNs, Registries, and Network AllocationsA plain guide to IP ownership: how ASNs and Regional Internet Registries work, what an IP ownership lookup actually tells you, and where to take it next.
Frequently asked questions
- What is a PTR record?
- A PTR (pointer) record maps an IP address back to a hostname, the reverse of an A or AAAA record. It lives in the special reverse-DNS zones (in-addr.arpa for IPv4, ip6.arpa for IPv6) and answers the question "what name belongs to this IP?".
- How do I use this tool?
- Enter a domain or hostname and the tool resolves its IP, then queries the matching reverse-DNS zone server-side and shows any PTR records it finds. You can also enter an IP directly to look up the name it points to; nothing you enter is stored.
- Why do PTR records matter?
- Many mail servers reject or flag messages from IPs that have no PTR record or whose PTR does not match the sending hostname (forward-confirmed reverse DNS). A correct PTR record improves email deliverability and helps logging, diagnostics and trust checks.
- How do I read or fix a PTR result?
- A healthy result shows a PTR that resolves forward to the same IP (forward-confirmed); an empty or mismatched result signals a problem. PTR records for public IPs are controlled by the network or hosting provider that owns the address block, so you usually request or set them through them, not in your own domain's DNS.
- Why does my IP have no PTR record even though my A record works?
- Forward records (A/AAAA) and reverse records (PTR) are managed separately, so setting one does not create the other. The reverse zone belongs to whoever controls the IP block, so a missing PTR must be added by your hosting or connectivity provider, not by editing your domain.