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What is SPF?

Learn how Sender Policy Framework helps prevent email spoofing.

What is SPF?

SPF (Sender Policy Framework) is an email authentication standard that allows a domain owner to specify which mail servers are authorized to send email on behalf of their domain. When a receiving mail server gets a message, it checks the sender's SPF record to verify that the sending IP address is authorized.

Example SPF Record

v=spf1 include:spf.protection.outlook.com -all

This record authorizes Microsoft 365 to send email for the domain while rejecting all other senders.

What Do SPF Results Mean?

ResultDescription
PassThe sender is authorized.
FailThe sender is not authorized.
SoftFailProbably unauthorized.
NeutralNo opinion.
NoneNo SPF record found.

Try Our DNS Lookup

Use our DNS Lookup tool to view SPF records for any domain.