What is SPF?
Sender Policy Framework — the first line of defense for email authentication.
SPF (Sender Policy Framework) is a DNS-based email authentication protocol that specifies which mail servers are authorized to send email on behalf of your domain. When a receiving server gets an email, it checks the sender's IP address against the SPF record published in DNS. If the IP matches, the email passes SPF authentication. Without SPF, your emails are more likely to be flagged as spam or rejected entirely — making it essential for cold email deliverability.