DKIM & SPF
Last updated: March 2025
Definition
Email authentication protocols that prove your emails are really from you. SPF (Sender Policy Framework) tells receiving servers which IPs can send mail for your domain. DKIM (DomainKeys Identified Mail) adds a cryptographic signature to each email. Together with DMARC, they're the foundation of email deliverability.
Why It Matters
Without SPF and DKIM, anyone can spoof your domain and send emails pretending to be you. Receiving servers check these records to decide if your email is legitimate. Missing authentication is the number one reason cold emails hit spam folders instead of inboxes.
How to Improve
- Set up SPF by adding a TXT record to your domain's DNS listing all authorized sending services.
- Configure DKIM through your email provider. They'll give you a TXT record to add to your DNS.
- Add a DMARC record that tells receiving servers what to do with emails failing SPF or DKIM checks.
- Test your setup using a mail tester tool. Send a test email and verify all three protocols pass. Fix failures before launching campaigns.