Sender Policy Framework, or SPF, is a verification system, that is employed to stop the so-called email spoofing where an e-mail message can be sent from one e-mail address, but to appear as being sent from another one, typically with the objective to scam the recipient in some way. When SPF protection is enabled for a domain, an exclusive record is generated for it in the Domain Name System and all DNS servers worldwide receive it. The record contains all email servers that are allowed to send valid messages from an email address part of the domain. When an email is sent, the first DNS server it encounters checks the SPF record and when the sending server is authorized, the message is sent to the targeted destination. If, however, the sending server is not contained in the SPF record for the particular domain, the e-mail message will not be submitted and it will be removed. When you employ this service, it'll stop third parties from sending spam messages which appear to have been sent from you.