Sender Policy Framework, or SPF, is a validation system, that is designed to prevent the so-called e-mail spoofing where an email message can be sent from one email, but to appear as being sent from another, often with the idea to fraud the recipient in some way. If SPF protection is enabled for a domain, a specific record is generated for it in the Domain Name System and all of the DNS servers globally have it. The record features all email servers that are allowed to send authentic messages from an e-mail address part of the domain. When an e-mail is sent, the first DNS server it encounters verifies the SPF record and if the sending server is permitted, the message is forwarded to the targeted receiver. When, however, the sending server is not present in the SPF record for the particular domain, the email message will not be sent and it'll be removed. When you employ this service, it'll stop third parties from sending spam messages which look as if they have been sent from you.