Email authentication is essential for ensuring your messages reach inboxes and aren't marked as spam. As a developer, you need to configure and validate SPF, DKIM, DMARC, and BIMI records correctly in your DNS settings to maintain sender reputation and support deliverability.

This hub covers practical steps for setting up and troubleshooting these authentication methods across different environments. Whether you're using Microsoft 365, Amazon SES, shared hosting, or custom domains with cloud providers, you'll find guidance on generating keys, publishing records, and confirming they’re functional through DNS lookup and verification tools.

You’ll also learn how to diagnose common failures—like DKIM signature mismatches, DMARC policy conflicts, and alignment issues—especially when sending bulk emails or using third-party platforms. Understanding how these systems interact, including alignment between DKIM and DMARC, helps you avoid delivery issues. This guide includes tips on monitoring DMARC reports, adjusting policies safely, and testing changes before deployment.

What you'll find in this hub

  • Step-by-step DKIM setup for Microsoft 365, Amazon SES, and Gmail
  • How to validate and troubleshoot DKIM records using DNS tools
  • Configuring DMARC policies for single and hybrid email environments
  • Interpreting DMARC aggregate reports for real-time feedback
  • Using BIMI to enhance brand visibility in email inboxes
  • Understanding TLS and secure email transmission protocols

Start here

Browse all 87 articles in Email authentication: SPF, DKIM, DMARC and BIMI →

Put it to work

Try the checks described here on your own data: verify an email address or a list with EmailListChecker.