Due to the fact that a significant majority of SPAM comes from forged addresses, a new Sender Policy Framework (SPF) standard is being implemented by a number of ISPs and mail hosts, including several major providers (Hotmail, Yahoo, AOL, etc). Those providers have begun to require SPF to allow mail through their networks. Mail systems will need SPF records for their domains if they want their mail to be accepted by those providers.
SPF is an open standard created to stop forgery of FROM addresses. SPF helps mail servers distinguish forgeries from real mail by making it possible for a domain owner to say,Â “I only send mail from these machines.” That way, if any other machines try to send mail from that domain, the mail server knows that the FROM address is forged.
To create an SPF Record go to http://old.openspf.org/wizard.html you will be getting a window shown like below
Just insert your domain and click on begin. Once you Â have finished it you will be getting the record which you need to file in the DNS.