Sender Policy Framework, or SPF, is a verification system, which is used to prevent the so-called e-mail spoofing where an e-mail message can be sent from one e-mail address, but to seem as being sent from another one, typically with the purpose to scam the recipient for some reason. When SPF protection is activated for a domain, an exclusive record is made for it in the Domain Name System and all DNS servers around the world get it. The record features all e-mail servers that are permitted to send valid 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 authorized, the message is forwarded to the targeted destination. When, however, the sending server is not contained in the SPF record for the specified domain, the e-mail message will not be forwarded and it will be removed. When you use this service, it will prevent third parties from sending spam emails that seem to have been sent from you.