How to Improve Email Deliverability with SPF, DKIM, and DMARC

Email is a crucial communication tool for businesses, but many struggle with poor deliverability rates. If your messages end up in the spam folder instead of your recipient’s inbox, you lose trust, leads, and potential revenue. Three of the most effective technologies to solve this problem are SPF, DKIM, and DMARC. These email authentication protocols help email servers verify that your messages are genuine and haven’t been tampered with.

Why Email Deliverability Matters

Imagine sending invoices, customer updates, or password resets, only for them to disappear into spam folders. This not only affects productivity but also damages your brand credibility. By implementing SPF, DKIM, and DMARC, you reduce spam risks and prove to receiving mail servers that your messages are trustworthy.

What is SPF?

Sender Policy Framework (SPF) allows domain owners to specify which mail servers are authorized to send emails on their behalf.

  • Example: If your website domain is example.com, you can create an SPF record in DNS that lists only your hosting or email servers.

  • When an email is sent, the receiving mail server checks the SPF record. If the server sending the message is not listed, the email may be flagged as suspicious.

How to set it up:

  1. Log into your DNS manager (e.g., cPanel, Cloudflare).

  2. Add a TXT record with your SPF policy, for example:

    v=spf1 include:spf.yourmailprovider.com -all

  3. Save and propagate the changes.

What is DKIM?

DomainKeys Identified Mail (DKIM) ensures that the content of your email hasn’t been altered during transit. It works by attaching a digital signature to every outgoing message.

  • This signature is generated using a private key stored on your mail server.

  • The recipient’s server verifies the signature using a public key stored in your DNS.

How to set it up:

  1. Generate DKIM keys from your mail server or hosting control panel.

  2. Add the public key as a TXT record in DNS.

  3. Enable DKIM signing in your email system.

What is DMARC?

Domain-based Message Authentication, Reporting, and Conformance (DMARC) builds on SPF and DKIM. It tells receiving mail servers what to do if a message fails authentication.

  • Example: Reject, quarantine (send to spam), or allow.

  • It also provides reports so you can monitor unauthorized email activity.

How to set it up:

  1. Add a TXT record in DNS, such as:

    v=DMARC1; p=quarantine; rua=mailto:dmarc-reports@example.com

  2. Start with a “monitor” policy before moving to stricter rules.

  3. Review reports to track suspicious email activity.

Best Practices for Deliverability

  • Use consistent sender names and addresses.

  • Avoid spammy subject lines like “FREE!!!” or “LIMITED TIME OFFER!!!”.

  • Regularly clean your email list to remove inactive addresses.

  • Monitor bounce rates and sender reputation using tools like Google Postmaster.

Conclusion

By properly configuring SPF, DKIM, and DMARC, you significantly improve your email deliverability. These technologies act as digital “passports” for your emails, proving that they are legitimate and safe. Combined with good email practices, they ensure that your messages reach the inbox, strengthen trust, and protect your brand from spoofing or phishing attacks.