Allows mail servers to distinguish forgeries from "genuine" e-mail from a domain; works before the message body is transmitted, saving ISPs and other e-mail recipients the bandwidth cost of downloading the message and the cost of filtering it.
a method whereby the owner of a domain can choose to specify which mail servers people who claim to be sending mail from that domain are allowed to use
A protocol used to eliminate email forgeries. A line of code called an SPF record is placed in a sender's Domain Name Server information. The incoming mail server can verify a sender by reading the SPF record before allowing a message through.
SPF fights return-path address forgery and makes it easier to identify spoofs. Domain owners identify sending mail servers in DNS. SMTP receivers verify the envelope sender address against this information, and can distinguish authentic messages from forgeries before any message data is transmitted.
In computing, Sender Policy Framework (SPF) is an extension to the Simple Mail Transfer Protocol (SMTP). SPF allows software to identify and reject forged addresses in the SMTP MAIL FROM (Return-Path), a typical nuisance in e-mail spam. SPF is defined in RFC 4408.