Sender Policy Framework, or SPF, is a verification system, which is intended to stop the so-called e-mail spoofing where an email message can be sent from one e-mail address, but to seem as being sent from another one, typically with the purpose to fraud the recipient in some way. If SPF protection is enabled for a domain name, a unique record is created for it in the Domain Name System and all DNS servers worldwide receive it. The record features all email servers that are allowed to send legitimate messages from an address within the domain. When a message is sent, the very first DNS server it encounters verifies the SPF record and in case the sending server is permitted, the message is forwarded to the targeted destination. When, however, the sending server is not contained in the SPF record for the given domain, the email message won't be sent and it will be discarded. In the event that you employ this solution, it will stop third parties from sending spam messages that seem to have been sent from you.