Sender Policy Framework (SPF) is a spam prevention method that works by specifying which servers are allowed to send e-mail for a domain. The owner of a domain (say: google.com) can place information in his domain records which servers are allowed to send e-mail on its behalf.
A common tactic amongst spammers is faking their identity, to leverage other peoples reputation. By using SPF, you can protect your reputation, and demonstrate legitimacy.
Our system checks whether you have SPF records, and if they're in order. It also provides advice on what to do.