Why Email Authentication Matters
Mailbox providers (Gmail, Outlook, Yahoo) require sending domains to be authenticated. Without SPF, DKIM, and DMARC your messages are likely to land in spam or be rejected. Authentication also protects your domain from spoofing and supports CAN-SPAM compliance.
1. SPF (Sender Policy Framework)
Publish a TXT record listing the servers allowed to send mail for your domain.
v=spf1 include:_spf.yourprovider.com ~all
2. DKIM (DomainKeys Identified Mail)
Add the public key your email provider gives you as a TXT/CNAME record. DKIM cryptographically signs each message so receivers can verify it was not altered.
selector._domainkey.yourdomain.com -> (value from provider)
3. DMARC (Domain-based Message Authentication)
Tell receivers what to do with mail that fails SPF/DKIM and where to send reports.
v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com; adkim=s; aspf=s
Start with p=none to monitor, then move to
p=quarantine and finally p=reject.
4. Verify & Record
- Use a checker such as MXToolbox to confirm all three records pass.
- Send a test to mail-tester.com.
- Once verified, check “SPF, DKIM & DMARC verified” under Company Settings → Compliance Checklist.
CAN-SPAM Reminders
- Accurate “From” and subject lines.
- Valid physical mailing address in every email.
- Clear, working unsubscribe honored within 10 business days.