SPF, which means Sender Policy Framework, is an email safety system, which is employed to confirm whether an email message was sent by a certified server. Using SPF protection for a particular domain name will prevent the counterfeiting of email addresses created with the domain. In simple words: activating this attribute for a domain generates a particular record in the Domain Name System (DNS) which includes the IP addresses of the servers which are permitted to send email messages from mail boxes using the domain. Once this record propagates worldwide, it will exist on all the DNS servers that route the Internet traffic. When an e-mail message is sent, the initial DNS server it uses tests whether it comes from an official server. When it does, it's sent to the destination address, but if it does not originate from a server indexed in the SPF record for the particular domain, it's discarded. In this way nobody can mask an email address then make it look as if you are sending spam messages. This technique is also identified as email spoofing.