What is SPF / DKIM / DMARC?
Email authentication protocols that prove a sending domain is legitimate and authorized.
Understanding SPF / DKIM / DMARC
SPF (Sender Policy Framework) lists which servers are allowed to send email from your domain. DKIM (DomainKeys Identified Mail) adds a cryptographic signature to verify the email wasn't modified in transit. DMARC (Domain-based Message Authentication) tells receiving servers what to do with emails that fail SPF or DKIM. All three must be configured correctly for reliable cold email deliverability.