Email data: A beginner’s guide to channel performance

Email is one of the most commonly used marketing tools and one of the easiest to overuse. Many departments send frequent emails without knowing how those messages are performing. Over time, this can lead to overload for both senders and recipients.

If you're looking to reduce effort, improve impact, or simply understand what’s working, here’s a simple guide to analyzing email performance with no advanced analytics degree required!

Core metrics to track

Start by understanding the basic metrics in your email platform:

• Open Rate: Shows how many recipients opened your email. A good indicator of subject line effectiveness and interest.
• Click-Through Rate (CTR): Reflects engagement with your content and if users are taking action.
• Bounce Rate: Tells you how many emails failed to reach inboxes—usually due to invalid addresses.
• Unsubscribe Rate: Helps track audience fatigue. Occasional unsubscribes are normal, but high rates could signal a problem.
• Deliverability Rate: The percentage of emails that reached recipients' inboxes. Aim for close to 100%.

Spot trends, not just outliers

One email doesn’t tell the whole story. Instead, look at trends over time. Here are some ways to get started:

• Check which subject lines are consistently opened and which are ignored. Open rate is a great metric for guidance.
• If possible, identify audience buckets and which are the highest and lowest performing.
• Emails are time sensitive. Identify which day of week and time gain the most traction.

Even a simple spreadsheet can help you spot trends like “Wednesday emails get better opens” or “Subject line A performs better than Subject line B.” Grouping subject lines by topics also helps see broader trends. Also see the blog post Eight tips for superior internal email subject lines.

Determine what is considered high and low performance

To make decisions, you need benchmarks. A general rule of thumb:

• Look at the average and mean for open rates. Below and above those thresholds are a great way to understand high and low performers.
• The same holds true with the click through rate. But be careful as some emails are built for click throughs, but are meant to be consumed isolated in the channel.

Segment and simplify

Email lists often include a wide range of audiences. Segmenting helps you:

• Identify where communication is effective
• Avoid overloading certain groups
• Tailor messages for better impact

You might find that some groups don’t need weekly emails—or that combining updates into a monthly digest improves clarity.

Use your data to work smarter

Data isn’t just for reporting. Use it to ask better questions:

• Can we consolidate low-performing topics?
• Are we overcommunicating with certain audiences?
• Which emails are worth the effort based on engagement?

The goal is to save time, reduce workload, and improve outcomes.

Final thought: Focus on value

It’s tempting to treat email as unlimited but your team’s time isn’t. By focusing on what drives engagement and trimming what doesn’t, you can reduce email volume, improve clarity, and better serve your audience.

While you’re here….

The Measurement and Analytics team recently launched a dedicated community of practice called The Digital Analytics Lab at the U where we offer office hours, a dedicated newsletter and, coming soon, webinars covering all things marketing analytics. 
Whether you are a beginner in Google Analytics or an advanced practitioner, we’d love to have you join!