1. Delivery Rate
Delivery rate shows how many emails successfully reached inboxes.
Formula:
Delivery Rate = (Emails Delivered ÷ Emails Sent) × 100
Low delivery rates may indicate problems with list quality or sender reputation.
2. Open Rate
Open rate measures the percentage of delivered emails that were opened.
While useful for subject line testing, open rates can be inflated due to privacy features. Treat them as directional rather than exact.
3. Click Through Rate
Click through rate measures how many recipients clicked a link in your email.
Formula:
CTR = (Clicks ÷ Emails Delivered) × 100
This metric reflects real engagement and interest.
4. Click To Open Rate
Click to open rate compares clicks to opens.
Formula:
CTOR = (Clicks ÷ Opens) × 100
This helps evaluate how compelling your email content and calls to action are after someone opens it.
5. Conversion Rate
Conversion rate tracks how many recipients completed a desired action such as making a purchase or signing up.
This is one of the most important performance indicators.
6. Unsubscribe Rate
Unsubscribe rate shows the percentage of recipients who opted out after receiving your email.
A consistently rising unsubscribe rate signals issues with relevance or frequency.
7. Bounce Rate
Bounce rate measures emails that could not be delivered.
High bounce rates harm sender reputation and should be addressed quickly.
8. Revenue Per Email
Revenue per email shows how much income each sent email generates on average.
Formula:
Revenue Per Email = Total Revenue ÷ Emails Sent
This KPI connects email performance directly to business growth.
9. List Growth Rate
List growth rate measures how quickly your subscriber base is expanding.
Healthy growth offsets natural unsubscribes and keeps your database fresh.
Final Thoughts
Do not track everything just because you can.
Focus on metrics that impact revenue and engagement:
- Click through rate
- Conversion rate
- Revenue per email
- List growth rate
When you optimize for meaningful KPIs, your email marketing becomes a predictable growth channel.