Sender Policy Framework (SPF) is a path-based Email Authentication technique that helps the receiving mail server detect spoofed sender addresses during email delivery.
SPF has become exceedingly vital in verifying which sending infrastructure can relay email on behalf of the domain. Implementing SPF for email will increase domain reputation and email protection. A valid SPF record will help protect from domain impersonation and email spoofing.
SPF is designed to help identify valid mail servers. Essentially, it is a DNS record which a domain owner publishes that contains a list of trusted servers from which emails can be sent from.
To set up your SPF policy, you must publish it in the form of a TXT record in your DNS. It works as an allow list for your domain where you are able to declare where emails from your domain can originate from. Unfortunately, this policy does not prevent spoofed emails from being sent in your name, but it allows receiving email servers to verify if the email was sent from a legit source that you own.