Sender Policy Framework, or SPF, is a verification system, that is employed to prevent the so-called email spoofing where an e-mail message can be sent from one email, but to appear as being sent from a different one, often with the objective to scam the recipient in some way. If SPF protection is enabled for a domain name, a specific record is generated for it in the Domain Name System and all the DNS servers globally receive it. The record includes all of the email servers that are allowed to send authentic messages from an email address part of the domain. When an e-mail is sent, the first DNS server it goes to verifies the SPF record and when the sending server is permitted, the message is sent to the target receiver. When, however, the sending server is not present in the SPF record for the specified domain, the email message will not be forwarded and it will be removed. In the event that you use this service, it will prevent third parties from sending spam e-mails which look as if they have been sent from you.