I remember when open rates were the gold standard in email marketing.
Marketers everywhere would hit send and watch the numbers climb, celebrating anything over 20% like it was Black Friday.
The problem is that open rates have become genuinely unreliable.
What changed?
Let's blame Apple, just a little.
When Apple launched Mail Privacy Protection (MPP), it started pre-loading email content before recipients actually opened anything. That means an email can register as "opened" even if nobody read it. Inflated open rates have made it nearly impossible to separate signal from noise. With other platforms following Apple's lead, we're now firmly in post-open-rate territory.
So, what should you be tracking?
Email marketing is still as effective as ever. It's just that the scoreboard has changed. Here's what to focus on instead.
1. Click-through rate (CTR)
Clicks don't lie. If someone clicks a link in your email, they were engaged. CTR gives you a much clearer picture of how relevant and compelling your content actually is.
Track it because:
- It shows action, not just interest
- It reflects how well your content matches your audience's needs
- It's measurable and consistent across platforms
Pro tip: If you're still watching open rates at all, pair them with click-to-open rate (CTOR). It tells you how well your content performs once an email is opened, which at least adds some context to a noisy number.
2. Conversion rate
This is where the money lives.
A conversion can be a purchase, a completed form, a booking, whatever goal your email was built around.
Track it because:
- It measures actual results, not proxy behaviours
- It ties email directly to ROI
- It helps you prioritise campaigns that perform
3. List growth and churn
Your list health tells a bigger story than any single campaign metric.
New subscribers are good. Unsubscribes are fine too, you're getting clearer on who your real audience is. But if your list is shrinking and clicks are dropping at the same time, that's a red flag worth investigating.
Keep an eye on:
- New subscriber numbers
- Unsubscribe rate
- Bounce rate
- Spam complaints
Good list hygiene will always beat chasing vanity metrics.
4. Email engagement over time
Don't judge campaigns in isolation. Look for patterns across multiple sends:
- Which content themes consistently perform well?
- Which days and times work best for your audience?
- Are certain segments more engaged than others?
Trend-tracking like this sharpens everything from your content strategy to your automation flows.
5. Revenue per email (RPE)
If you run e-commerce campaigns or any sales-driven sends, this is the metric your stakeholders actually care about.
How much revenue does each email generate on average?
RPE = Total revenue / Number of emails sent
Track it because:
- It's the clearest link between email and your bottom line
- It shifts your focus from engagement to profitability
- It's the number that tends to end budget conversations quickly
Stop obsessing over opens
Open rates were never perfect. They were just the easiest number to watch.
Now there's an opportunity to build a more accurate view of email performance. Focus on clicks, conversions, list health, and revenue. Those are the numbers that tell you whether your programme is actually working.
Want to talk email strategy?
At TouchBasePro, we help you send the right emails to the right people, and give you the reporting to know the difference.
Frequently asked questions
- Why are open rates no longer a reliable email marketing metric?
- Apple's Mail Privacy Protection pre-loads email content before a recipient opens it, which causes emails to register as 'opened' even when they weren't. Other platforms have introduced similar features, so open rate data is now widely inflated and unreliable.
- What is click-to-open rate (CTOR) and why does it matter?
- CTOR measures how many people who opened your email also clicked a link. It tells you how well your content performs once someone is inside the email, which adds more context than raw open rates alone.
- How do you calculate revenue per email?
- Divide the total revenue attributed to a campaign by the number of emails sent. It gives you a direct measure of what each send is worth to your bottom line.
- What list health metrics should email marketers track?
- Monitor new subscriber numbers, unsubscribe rate, bounce rate, and spam complaints together. A rising unsubscribe rate on its own isn't necessarily bad, but when combined with falling clicks it signals a deeper problem with audience fit or content relevance.