Tool · 14
Reverse DNS Lookup
Check the PTR record and forward-confirmed rDNS – the prerequisite for large providers accepting your mail.
Result for 216.73.216.193
No PTR record
| Address | PTR record | FCrDNS |
|---|---|---|
| 216.73.216.193 IPv4 | No PTR record | Not confirmed |
- ⚠ No PTR record exists for this address. Many mail servers reject connections from addresses without reverse DNS outright. The record is set by the operator of the IP network, not by your domain registrar.
What reverse DNS and FCrDNS mean
The PTR record maps an IP address to a name - the opposite direction of a normal lookup. Forward-confirmed rDNS goes one step further: the name from the PTR must resolve back to the same address via A or AAAA. Only then is it not freely assertable, because the two sides live in different zones - the PTR zone at the network operator, the forward zone at the domain owner. For mail servers this is effectively mandatory.