MAY BE HELPFUL TO SIMPLIFY SENDER POLICY FRAMEWORK (SPF) RECORDS

SPF flattening is a technique used to simplify Sender Policy Framework (SPF) records and reduce the number of DNS (Domain Name System) lookups needed to validate emails.

SPF flattening involves replacing nested SPF records with a single flat record that includes all the IP (Internet Protocol) addresses authorized to send email for a particular domain.SPF flattening is useful when a domain has multiple email systems, subdomains, or third-party services authorized to send emails on its behalf, as it can significantly reduce the number of DNS lookups required to validate SPF records. This, in turn, can improve email deliverability and reduce the risk of email being marked as spam.

SPF flattening can be achieved using a DNS resolver that can recursively traverse the SPF records, extract all authorized IP addresses, and create a flat SPF record. Alternatively, some email security services and providers offer SPF flattening as a feature to simplify SPF records and improve email authentication.

It is important to note that while SPF flattening can simplify SPF records, it can also increase the size of the SPF record, which can lead to other issues with email delivery and authentication. Therefore, it is important to test and monitor the effectiveness of SPF flattening on a domain's email delivery and authentication.

Often, "cleaning up" unused SPF entries or using SPF Macros can achieve similar results.