SPF (Sender Policy Framework)

What is SPF (Sender Policy Framework) ?

Sender policy framework (SPF), is a security measure that authenticates the IP address of the email sender. It is a list of IP addresses that are permitted to send email from the particular domain and authenticates that the email sent from the particular domain is in fact from that particular domain. The recipient’s mail server assesses the sending IP address in the public Domain Name System (DNS) to confirm it is permitted to send the email from the sender. The SPF verifies the HELO identity (the sending mail server) and the MAIL FROM identity (the email address the message is sent from). SPF reduces the possibility legitimate business email might be mistake for spam.