Sender Policy Framework, or SPF, is a validation system, which is intended to stop the so-called e-mail spoofing where an email message can be sent from one email, but to seem as being sent from a different one, usually with the objective to scam the recipient someway. When SPF protection is activated for a domain, a special record is created for it in the Domain Name System and all the DNS servers worldwide have it. The record features all of the e-mail servers that are allowed to send authentic messages from an email address part of the domain. When an e-mail is sent, the very first DNS server it encounters verifies the SPF record and when the sending server is permitted, the message is forwarded to the target destination. In case, 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 removed. When you use this solution, it will stop third parties from sending spam messages that seem to have been sent from you.