Knowledge Bank

Sender Policy Framework (SPF) is a method of e­mail validation designed to reduce spam.  It does this by addressing a security flaw in Simple Mail Transfer Protocol (SMTP) that allows sender addresses to be forged. Often referred to as 'e­mail spoofing', this allows a computer to send an email with a fake sender address to disguise it's true address.
This paper will look briefly at how 'spoofing' works, and the methods that SPF uses to address the security issues with SMTP. It will include a description of the SPF record syntax and details of how to set up some basic records. Throughout this paper all examples will use the current version of SPF – also known as SPFv1 or SPF Classic.