A Sender Policy Framework (SPF) Is an email authentication practice that is used to prevent spammers and scammers from sending spoofed emails on behalf of your domain. Similar to how DMARC and DKIM work, an SPF record published within the DNS of a domain allows email servers who receive mail from your domain to verify the authenticity of the message.
How Does Sender Policy Framework (SPF) Work?
In simple terms, a Sender Policy Framework (SPF) is a DNS record that you add to your domain where you can specify the IP Addresses/Email Servers that are authorized to send mail under the specified domains. The server receiving this incoming mail will receive a packet of information before the email being delivered specifying where this piece of mail is coming from. This packet of information will be then validated by the DNS records of the associated domain. If they match, then the mail will be delivered accordingly. If they do not match, they will be marked as being suspicious and denied by the receiving mail server.
Why Should I Implement SPF?
Implementing an SPF record alongside proper DMARC and DKIM settings for your domain will drastically increase the overall deliverability rates of all outgoing mail coming from your domain.