Given an IP address, return the PTR record. Useful when confirming an outbound mail server's rDNS matches its EHLO banner (missing or mismatched PTR is a classic spam-filter trip), tracing who owns a suspicious IP, or validating an auto-assigned PaaS hostname.
This tool is a one-shot check. PhishFence watches your domain 24/7 for DMARC changes, new lookalike registrations, and spoofing attempts.