Sender Policy Framework, or SPF, is a validation system, which is intended to prevent the so-called email spoofing where an e-mail message is sent from one email address, but to look as being sent from a different one, frequently with the purpose to fraud the recipient in some way. If SPF protection is activated for a domain, an exclusive record is made for it in the Domain Name System and all of the DNS servers around the world get it. The record includes all e-mail servers that are permitted to send valid messages from an e-mail address part of the domain. When a message is sent, the first DNS server it encounters verifies the SPF record and if its sending server is authorized, the message is forwarded to the target receiver. In case, however, the sending server is not present in the SPF record for the particular domain, the message will not be sent and it will be removed. When you use this solution, it will stop third parties from sending spam emails which seem to have been sent from you.