What does the PTR mechanism mean?
When an email receiver gets an email and the PTR mechanism is integrated in the sender’s SPF record, the receiver will look at the incoming IP address and do a “PTR” lookup. For example, if the sender is sending email from IP address 1.2.3.4, the receiver will perform a PTR lookup of 1.2.3.4 to attempt to retrieve a hostname. Lastly, if a hostname is discovered for IP address 1.2.3.4, then that hostname’s domain is compared to the domain that was originally used to lookup the SPF record.
Related Articles
What is a RUA report?
It is an aggregated report, which gives the data of the IP, PTR( Code of the SPF record), Reporter, Location, Date, DKIM Selector, DKIM Domain and Domain.
What is the difference between RUA and RUF reports?
RUA reports share the information regarding an email such as its sender IP and PTR, while RUF reports share the dmarc failed report for all unauthenticated emails to the assigned email ID.
How Smart SPF Works?
TDMARC is an industry-leading cybersecurity tool, designed to monitor three standard email authentication protocols- SPF, DKIM and DMARC, for complementing the Simple Mail Transfer Protocol (SMTP). It offers the Smart SPF feature to monitor and ...
What Is FCrDNS?
Forward-confirmed reverse DNS (FCrDNS) is also known as full-circle reverse DNS, double-reverse DNS. It shows the relationship Between IP address and domain name (Hostname). Most mail transfer agents use FCrDNS verification and if in case, there is ...
SPF DNS Lookup Limit?
SPF DNS Lookup Limit – “Too many DNS lookups” error Due to the SPF specification limit, the maximum number of DNS lookups allowed is 10. The SPF will fail if your SPF record results in more than 10 DNS lookups. The mechanisms which are counted ...