Sender Policy Framework

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Sender Policy Framework

SPF (Sender Policy Framework) is an email validation technique that helps prevent spam by verifying that an email supposedly from a specific domain was actually sent from a server authorized by that domain. It accomplishes this by creating a record within the Domain Name System (DNS) that lists the IP addresses or hostnames of authorized servers.

What does Sender Policy Framework mean?

The Sender Policy Framework (SPF) is an email authentication Protocol that verifies the authorized senders of an email. It does this by checking the IP address of the email sender against a list of authorized IP addresses published by the email owner. SPF helps prevent email spoofing, which is when an email is sent from a forged sender address.

SPF works by adding a TXT Record to the Domain Name System (DNS) for the domain that owns the email address. The TXT record contains a list of IP addresses that are authorized to send email on behalf of that domain. When an email server receives an email, it checks the SPF record for the sender’s domain. If the sender’s IP address is not included in the SPF record, the email server will reject the email as Spam.

SPF is a simple and effective way to prevent email spoofing. It is supported by most major email providers, including Gmail, Yahoo Mail, and Microsoft Outlook.

Applications

SPF is used to prevent email spoofing, which can be used for a variety of malicious purposes, including:

  • Phishing: Spoofed emails can be used to trick users into giving up their personal information, such as their passwords or credit card numbers.
  • Spam: Spoofed emails can be used to send large volumes of unwanted email, which can clog up email inboxes and waste time.
  • Malware: Spoofed emails can be used to distribute malware, which can damage computers and steal data.

SPF is an important tool for preventing email spoofing and protecting users from the associated risks.

History

SPF was developed in 2000 by Paul Vixie, the creator of BIND, the most widely used DNS server software. SPF was standardized in RFC 4408 in 2006.

SPF has been widely adopted by email providers and is now one of the most important email authentication protocols.