Reverse DNS (PTR) Lookup
Find the hostname an IP address points back to. Mail servers check this before accepting email.
Free, no account needed.
Why reverse DNS matters for email
Many receiving servers reject or distrust mail from an IP with no reverse DNS, or with a generic name that looks residential. A sending server should have a PTR record naming a hostname that points back to the same IP (forward-confirmed reverse DNS).
Reverse DNS is set by whoever controls the IP address, usually your hosting or cloud provider, not in your domain's DNS.
Frequently asked questions
How do I change my PTR record?
Through your server or IP provider's control panel, or by asking their support. Your domain registrar can't change it.
Related tools
- Email Blacklist CheckCheck an IP address or domain against widely used DNS blocklists, the lists mail servers consult to reject spam.
- SMTP Server TestConnect to a mail server on port 25 and check its greeting, STARTTLS support and TLS certificate, just as a sending server would.
- Dig: Online DNS LookupQuery any DNS record type the way the dig command does, from Google Public DNS or Cloudflare, with TTLs, the response status and DNSSEC validation.