Sender Policy Framework, or SPF, is a verification system, which is used to prevent the so-called e-mail spoofing where an email message is sent from one email address, but to look as being sent from another one, frequently with the idea to scam the recipient someway. If SPF protection is enabled for a domain, a unique record is generated for it in the Domain Name System and all DNS servers globally get it. The record contains all the mail servers that are allowed to send authentic messages from an address under the domain. When an e-mail is sent, the first DNS server it encounters verifies the SPF record and when the sending server is permitted, the message is sent to the targeted receiver. When, however, the sending server is not contained in the SPF record for the specified domain, the email message will not be submitted and it will be removed. Whenever you employ this solution, it'll prevent third parties from sending spam e-mails that appear to have been sent by you.