Webopedia on Google+Webopedia on TwitterWebopedia on FacebookTech Bytes Blog
Main » TERM » S »


Short for Sender Policy Framework, an extension of SMTP that stops e-mail spammers from forging the "From" fields in an e-mail. As SMTP itself does not carry an authenticating mechanism, the SPF extension provides the authentication scheme by specifying which computers are authorized to send email from a specific domain. In order to use SPF, the domain sending e-mails must establish an SPF record that is published in DNS records. When the e-mail passes through the DNS server, it is compared to the SPF record for that domain to determine if the sender is indeed authorized to transmit e-mails from that sender's address. If the e-mail comes from a domain that is not authorized, the DNS server will not forward the e-mail to the expected destination.

SPF is one method that can be used to stop spam from being sent using unauthorized domain names. However, it should be noted that SPF only stops the spammer from forging the "From" field in the e-mail and does not stop the spammer from sending e-mails from a domain in which it is a member.

SPF was formerly called Sender Permitted Form, but the name was later changed while the abbreviation remained the same.

The Problem with Statistics

We look at a few of the more troubling aspects of statistics and how these may be used to advance an agenda or skew the facts to someone's... Read More »

29 Free Android Apps for Cash-Strapped Students

From wacky alarm clocks to lecture hall tools and after class entertainment, these Android apps are a good fit for a student's life and budget. Read More »

Sharing Threat Intelligence

A growing number of startups make the sharing of threat intelligence a key part of their solutions. Read More »

The 7 Layers of the OSI Model

The Open System Interconnection (OSI) model defines a networking framework to implement protocols in seven layers. Use this handy guide to compare... Read More »

Network Fundamentals Study Guide

Networking fundamentals teaches the building blocks of modern network design. Learn different types of networks, concepts, architecture and... Read More »

Computer Architecture Study Guide

This Webopedia  study guide describes the different parts of a computer system and their relations. Read More »