SPF (Sender Policy Framework) is an email authentication standard that helps prevent spoofing. It works by specifying which mail servers are authorized to send emails on behalf of a domain. This allows receiving servers to verify whether an email is legitimately sent from the claimed domain, reducing the risk of phishing and spam.

How does SPF work?

SPF uses DNS (Domain Name System) to publish a list of authorized sending servers via an SPF record — a type of TXT record in the domain’s DNS zone. When a receiving mail server gets an email, it checks the sender domain’s SPF record to confirm whether the sending IP matches an approved source.

For example, if your organization sends emails via Microsoft 365 and Mailchimp, both must be included in your SPF record. Emails sent from other servers may be flagged or rejected, depending on the SPF policy.

Importance for cybersecurity

SPF helps prevent cybercriminals from spoofing your domain name in phishing attacks. It’s an essential layer of email security, especially as email remains a common vector for cyber threats.

However, SPF alone is not enough. It verifies only the sending server, not the message content or the “friendly from” name users see. That’s why SPF is often combined with DKIM (DomainKeys Identified Mail) and DMARC (Domain-based Message Authentication, Reporting & Conformance) for complete protection.

SPF and RiskStudio

RiskStudio helps organizations assess the cybersecurity posture of their suppliers — including how well their email domains are protected. Through automated scans, we check whether suppliers have valid SPF records and if they implement additional controls like DKIM and DMARC. Instantly spot vulnerabilities to email spoofing and take action before a threat materializes. This way, you secure both your organization and your digital supply chain.