What is a SPF Record?
Sender Policy Framework (SPF) is an email validation system designed to prevent email spam by detecting email spoofing. Email spoofing is a common vulnerability, SPF solves this by verifying the senders IP address.
SPF allows administrators to specify which hosts are allowed to send mail from their domain; this is done by creating a specific SPF record (or TXT record) in the Domain Name System (DNS). Mail exchangers use the DNS to check that mail from a given domain is being sent by a host sanctioned by that domain’s administrators.