Testing email deliverability before sending ensures your messages reach inboxes, not spam folders. This process involves evaluating multiple factors—spam scores, authentication setup, sender reputation, and client-specific rendering—before your campaign goes live. By running these checks early, you reduce the risk of delivery failures and increase the chances your audience sees your content.

Key steps include checking spam scores using real-world inbox conditions, running seed tests across major email clients, and validating inbox placement in both primary and spam folders. These tests help uncover issues like broken links, incorrect headers, or poor formatting that could trigger filtering. You should also test how your email displays in dark mode, across different devices, and with assistive technologies to ensure accessibility and consistent rendering.

Understanding the results requires knowing what each test measures: low spam scores, high inbox placement rates, and accurate rendering across clients indicate strong deliverability. This hub walks you through the tools and workflows needed to run accurate tests, interpret results, and take action to improve your email’s performance.

What you'll find in this hub

  • How to run seed tests and interpret inbox placement results
  • Methods for evaluating spam scores in real inbox environments
  • Testing email rendering across Gmail, Outlook, Apple Mail, and other major clients
  • Dark mode compatibility and color contrast checks
  • Accessibility audits using screen readers and keyboard navigation
  • How to validate authentication settings (SPF, DKIM, DMARC) and sender reputation

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Put it to work

See how your own emails score: run a deliverability test with MailTester.