SPF
Sender Policy Framework, an email authentication signal that checks whether a sending server is authorized for a domain.
Why it matters
SPF can help evaluate sender legitimacy, but forwarding and configuration issues can affect results.
Example pattern
Authentication-Results includes spf=fail for a business-looking sender.
How CheckLink can help
CheckLink can surface SPF text found in pasted headers for manual context.
Related terms
Related guides
Check the signal in context
Security terms are useful, but real decisions need context. Use CheckLink to inspect available signals before you click.