Sender Policy Framework, or SPF, is a verification system, which is designed to stop the so-called e-mail spoofing where an e-mail message is sent from one e-mail address, but to seem as being sent from a different one, typically with the objective to fraud the recipient in some way. When SPF protection is enabled for a domain name, an exclusive record is created for it in the Domain Name System and all of the DNS servers around the world get it. The record contains all the email servers that are permitted to send valid messages from an address under the domain. When an e-mail is sent, the very first DNS server it encounters verifies the SPF record and if the sending server is authorized, the message is forwarded to the targeted destination. In case, however, the sending server is not included in the SPF record for the given domain, the e-mail message will not be sent and it will be removed. When you use this service, it will stop third parties from sending spam messages that appear to have been sent by you.