Sender Policy Framework, or SPF, is a validation system, which is employed to stop the so-called email spoofing where an email message can be sent from one e-mail address, but to appear as being sent from a different, ordinarily with the idea to scam the recipient in some way. If SPF protection is activated for a domain name, a special record is created for it in the Domain Name System and all of the DNS servers around the world get it. The record includes all of the email servers that are permitted to send authentic messages from an address under the domain. When a message is sent, the very first DNS server it goes to checks the SPF record and when the sending server is authorized, the message is forwarded to the target receiver. If, however, the sending server doesn't exist in the SPF record for the particular domain, the email message won't be submitted and it will be discarded. If you employ this solution, it'll stop third parties from sending spam emails that seem to have been sent by you.