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Sender Policy Framework (SPF) Defined

Sender Policy Framework (SPF) is an email authentication protocol used to prevent email spoofing and phishing by verifying the sender's identity. SPF allows domain owners to publish a list of authorized mail servers that are permitted to send emails on behalf of their domain. When an email is received, the recipient's mail server checks the SPF record of the sender's domain to verify if the sending server is authorized to send emails for that domain. If the sending server is not listed in the SPF record, the recipient's mail server may mark the email as potentially fraudulent or reject it altogether.

SPF records are DNS (Domain Name System) records containing information about authorized sending mail servers for a domain. By implementing SPF, domain owners can improve email deliverability, reduce the risk of email spoofing attacks, and enhance the overall security and authenticity of email communications.

How to Use it in a Sentence

Implementing Sender Policy Framework (SPF) for your domain can help protect against email spoofing and phishing by verifying the authenticity of email senders.

Common FAQs

Sender Policy Framework (SPF) is an email authentication protocol designed to prevent email spoofing and phishing by verifying the sender's identity. It allows domain owners to specify which mail servers are authorized to send emails on behalf of their domain.

SPF records are DNS (Domain Name System) records that specify the authorized mail servers for a domain. These records include a list of IP addresses or hostnames of servers permitted to send emails on behalf of the domain. SPF records are published in DNS TXT records and are used by receiving mail servers to authenticate incoming emails.

Learn more about OneSignal DNS Authentication.

SPF is important for enhancing email security and reducing the risk of email spoofing attacks. By implementing SPF, domain owners can protect their domains from unauthorized use in spoofed or phishing emails, thereby improving email deliverability and maintaining sender reputation.

Listen to our podcast where we talk to an email specialist about why email deliverability is so important, avoiding spam traps, and other email list best practices.

If a domain does not have an SPF record published, recipient mail servers may treat emails from that domain with caution. Without SPF, there is no explicit way for receiving servers to verify the legitimacy of email senders, potentially leading to higher rates of spam filtering or email rejection.

While SPF helps prevent email spoofing and phishing attacks by verifying sender identities, it does not protect against all email-related threats (e.g., malware attachments, social engineering attacks). Additional email security measures such as DKIM (DomainKeys Identified Mail) and DMARC (Domain-based Message Authentication, Reporting, and Conformance) should be used in conjunction with SPF for comprehensive email protection.

OneSignal streamlines the email authentication process for our customers, making it easier and quicker to start messaging your audience. For more detailed information, check out our complete guide to DNS Authentication video and view our DNS authentication documentation.