SPF (Sender Policy Framework)

What's on the horizon for email identity? This section looks at what's next, from new RFCs to advanced identity verification techniques, and prepares you for the next wave of email security.

26 questions in this topic

What is SPF? What problem was SPF created to solve? Why is SPF important for email deliverability? How does SPF work? How does SPF validation actually happen during SMTP? What does an SPF record look like? Where do I publish an SPF record? What are SPF mechanisms (e.g., ip4, a, mx, include)? What are ptr, exists, exp, and macro mechanisms? What are SPF qualifiers (e.g., +, -, ~, ?)? What's the difference between -all and ~all in SPF? How do “softfail (~all)” vs “fail (-all)” vs “neutral (?all)” behave? What is the difference between include: and redirect:? What is the SPF 10-DNS-lookup limit? What is the SPF 10-lookup limit and why does it exist? What happens when an SPF record exceeds DNS lookup limits? How do I fix "Too many DNS lookups" for SPF? What is SPF flattening? What is SPF flattening and when should you avoid it? Does SPF prevent domain spoofing? Why does SPF alone not prevent spoofing? How do I check if my SPF record is valid? How can you debug SPF failures? What happens when multiple SPF records exist on a domain? Why do sub-domain SPF records behave differently? What are common myths about SPF causing delivery issues?

Questions about SPF (Sender Policy Framework)