Email marketing comes with a huge range of metrics — from opens and clicks to unsubscribes and spam complaints. But amid this flood of data, there are key metrics worth tracking first. They're the ones that give you an objective picture of your newsletter's performance and help you make the right decisions. In this article, we break down which metrics matter most and why they're important for analysis.

Why tracking metrics matters

  • Metrics help you understand how your audience interacts with an email
  • Evaluating each stage of the funnel — from open to conversion — helps you spot weak points
  • Comparing metrics helps you test hypotheses and improve campaign performance
  • Regular analysis reduces the risk of mistakes and wasted budget

For more on understanding audience engagement, see the article "How to Gauge Subscriber Engagement Through Metrics."

Key metrics for evaluating emails

  1. Open Rate (OR) Shows how many people opened the email. An important indicator of the subject line, preheader, and sender reputation. But Open Rate alone doesn't guarantee success — it's important to look at what happens next.
  2. Click-Through Rate (CTR) The share of subscribers who clicked at least one link. Shows how well the content and offer engage the audience.
  3. Click-to-Open Rate (CTOR) The ratio of clicks to opened emails. Helps you understand how interesting the email was for those who actually opened it.
  4. Conversion Rate The percentage of users who completed the target action — a purchase, a form submission, a registration. The main indicator of a newsletter's business result.
  5. Bounce Rate The share of emails that weren't delivered to recipients. A high bounce rate hurts your reputation and lowers deliverability.
  6. Unsubscribe Rate The percentage of people who unsubscribed. A signal about content relevance, sending frequency, and database quality.
  7. Complaint Rate (spam complaints) A very important metric for your domain's reputation. Even a small number of complaints can hurt deliverability. For more on sending requirements, see Google's official help documentation.

If you want to understand how to build reports and view all this data in one place, we recommend the article "How to Set Up Reports in Yandex Metrica for Email Campaigns."

How to interpret key email metrics

  • High OR and low CTR → interesting subject line, but weak content
  • High CTR and low Conversion Rate → problems on the website or with the offer
  • High Bounce Rate → problems with database quality
  • Rising unsubscribes → outdated or irrelevant content

Which metrics matter to whom

  • For marketing → OR, CTR, CTOR
  • For the business → Conversion Rate, revenue, ROI
  • For technical specialists → Bounce Rate, Complaint Rate

Don't forget to regularly test subject lines, preheaders, and offers — read more about this in the article "How to Boost Open Rate Through Subject Line Testing."

Conclusion

No single metric gives you the full picture of performance. Evaluating emails always comes down to a combination of indicators. Regular analysis helps you not just measure but actually improve your newsletters, achieve better results, and build audience loyalty.If you work in Letteros, all of these metrics are collected automatically — from open to conversion — with no complicated setup.