Email Marketing Metrics: What to Measure and What to Ignore

After every send, your email platform shows a dashboard full of percentages. Some of these numbers tell you whether your emails are working; others mostly tell you whether they were delivered. This guide explains each common email marketing metric and which ones deserve your attention.

The main metrics explained

Metric	What it means	How to read it
Delivery rate	Share of emails accepted by recipients' mail servers	Should be very high; a drop points to list or setup problems
Bounce rate	Emails rejected, permanently (hard) or temporarily (soft)	Remove hard bounces promptly
Open rate	Share of delivered emails recorded as opened	Useful for trends, unreliable as an exact figure
Click rate	Share of delivered emails where someone clicked a link	One of the best everyday measures of interest
Click-to-open rate	Clicks as a share of opens	Shows how well the content worked once opened
Conversion rate	Share of recipients who did what you wanted: bought, booked, replied	The number that matters most
Unsubscribe rate	Share who left the list after a send	A spike means the email missed the mark
Spam complaint rate	Share who marked the email as spam	Keep it as close to zero as possible

Why open rates are less reliable now

An "open" is usually recorded when a tiny invisible image in the email loads. Apple's Mail Privacy Protection, available on its devices, loads email content privately in the background, which can register opens even when the person has not read the message. Other email apps and security tools can do something similar. As a result, open rates can look higher than real readership, and they vary with how many of your readers use such apps.

Opens are still useful for comparing subject lines within your own list over time, but do not treat them as proof that people read your email. Clicks and actions are firmer evidence.

The numbers a small business should track

1. Results against your goal: bookings, sales, replies or downloads that came from the email. Use tracked links or unique offer codes so you can attribute them.
2. Click rate: how many people found something worth clicking.
3. List growth: new subscribers minus unsubscribes, monthly.
4. Unsubscribes and spam complaints: early warning that something is off.

Spam complaints deserve particular care. Large providers such as Gmail publish guidance asking bulk senders to keep complaint rates very low, and high complaint rates can push your future emails into spam folders.

How to track sales from email

• Add tracking tags to links (often called UTM parameters). Most platforms can add them automatically, and analytics tools then show visits and sales from each campaign.
• Use a code unique to the email for offers redeemed in person or by phone.
• Ask: a "how did you hear about us?" question at booking captures what tracking misses.

Benchmarks: use with care

Platforms and agencies publish average open and click rates by industry. They can be a rough reference, but averages mix very different lists and are distorted by automatic opens. The most useful benchmark is your own: compare each email with your previous ones and look for trends.

What to do with the numbers

• Low clicks, normal opens: the subject worked but the content or offer did not. Simplify the email and sharpen the main action.
• Rising unsubscribes: you may be sending too often or off-topic for what people signed up for.
• Bounces creeping up: clean the list and check how addresses are collected.
• Clicks but no sales: look at the page people land on, not the email.

For ideas on improving each stage, see our email marketing tips.