Email

What Are SPF, DKIM, and DMARC? Why Your Business Email Needs All Three

SPF, DKIM, and DMARC are the three DNS records that protect your business domain from email spoofing and improve your email deliverability. Here's what they do in plain English.

Have you ever received an email that appeared to be from a legitimate company but was actually spam or phishing? That's email spoofing — attackers faking the 'From' address to impersonate your business. SPF, DKIM, and DMARC are the technical standards that prevent this. Without them, anyone can send email that appears to come from your domain.

SPF: Sender Policy Framework

SPF is a DNS record that lists which mail servers are authorized to send email on behalf of your domain. When a receiving server gets an email claiming to be from your@yourdomain.com, it checks your SPF record to confirm the sending server is on the approved list. If it's not, the email fails SPF — a red flag for spam filters.

DKIM: DomainKeys Identified Mail

DKIM adds a cryptographic signature to every outgoing email. The receiving server verifies this signature against a public key in your DNS records. A valid DKIM signature proves the email wasn't tampered with in transit and really came from your mail system. It's the digital equivalent of a wax seal.

DMARC: Domain-Based Message Authentication

DMARC sits on top of SPF and DKIM and tells receiving servers what to do when an email fails those checks — quarantine it (send to spam), reject it (block it entirely), or take no action (monitor only). DMARC also sends you reports about emails being sent using your domain, which is how you discover if someone is spoofing your brand.

Why All Three Matter for Your Business

Google and Yahoo now require SPF, DKIM, and DMARC for senders of bulk email. Microsoft also uses these records as significant factors in spam scoring. Businesses without these records often have legitimate emails landing in spam folders. If you're on Microsoft 365 or Google Workspace and haven't configured these records, contact your IT provider today.