What is SPF (Sender Policy Framework)?
Turkish: SPF
SPF is an email authentication control that publishes approved sending servers in DNS, helping receivers spot spoofed domain mail.
What is SPF?
SPF (Sender Policy Framework) is an email authentication mechanism where a domain publishes which mail servers are allowed to send messages for it. When a receiving mail server gets a message, it checks the envelope sender domain against that domain’s SPF TXT record in DNS and compares the sender IP address with the approved list.
An SPF record usually starts with v=spf1 and uses mechanisms such as ip4, ip6, a, mx, and include to describe valid senders. The final ~all or -all tells receivers how to treat sources that are not listed. If a company sends through both Google Workspace and an email automation platform, both services must be represented in the record.
Limits and Operational Use
SPF does not secure the visible From header by itself, and forwarding can break SPF alignment because the forwarding server becomes the apparent sender. For that reason SPF is normally paired with DKIM signatures and a DMARC policy.
In business systems, SPF protects invoices, password resets, proposals, and campaign emails from being rejected or treated as spoofed mail. The practical work is ongoing: keep the DNS record narrow, remove old vendors, avoid unnecessary broad includes, and monitor which systems are allowed to send through SMTP.
Related Terms
DKIM adds a cryptographic signature to email so receiving servers can verify that a domain authorized and preserved the message.
DMARC (Domain-based Message Authentication, Reporting, and Conformance)DMARC combines SPF and DKIM results with domain policy and reporting so email senders can reduce spoofing and phishing risk.
Email DeliverabilityEmail deliverability measures whether sent messages reach the recipient's inbox instead of being rejected, delayed, or placed in spam.
SMTP (Simple Mail Transfer Protocol)SMTP is the standard transfer protocol that sends email from clients to mail servers and relays it between servers toward the recipient domain.