20 Email Marketing KPIs You Should Be Tracking in 2026

392.5 billion emails. Every day. That's the number for 2026 according to Statista. And the average click-through rate? 2.09%. MailerLite pulled that from 3.6 million campaigns. Read that again.

That's a stupid amount of emails going nowhere.

Take Mike. Runs email for a mid-size SaaS company. About 40,000 sends a month. His boss goes: "How are emails doing?" Mike says: "Opens are 44%!" Everyone's happy. But nobody's buying. Pipeline hasn't moved. Revenue from email? Flat.

Mike's been watching the wrong numbers. And honestly most marketers are doing the same thing.

Here's the worst part. Apple's Mail Privacy Protection messed up open rates for a huge chunk of inboxes. So Mike might be celebrating numbers that literally mean nothing.

You need more than just opens. You need email marketing KPIs that cover the whole picture. Deliverability. Engagement. Conversions. Strategy. That's what this guide is. Twenty KPIs. Five categories. Each one gets a formula, a benchmark, and something you can actually do about it.

Doesn't matter if you're running newsletters or cold email outreach strategies. These email metrics will tell you what's working. And what's wasting your time.

Let's go.

Deliverability & List Health KPIs

Your emails have to arrive first. Obvious right? But tons of campaigns die right here.

If stuff lands in spam or bounces back, nothing else matters. Every other email campaign metric you track depends on this group.

1. Delivery Rate

Formula: (Emails Delivered / Emails Sent) × 100

What percentage actually made it? EmailToolTester ran tests in 2025. ActiveCampaign came first with 94.2% deliverability. That's your target.

Below 90%? Something's broken. Could be sender reputation. Could be garbage data. Could be you're missing email authentication requirements. Fix this before worrying about anything else.

2. Bounce Rate (Hard vs Soft)

Formula: (Bounced Emails / Emails Sent) × 100

Hard bounces = address doesn't exist. Person left. Email's fake. Whatever. Soft bounces = temporary stuff. Full inbox. Server hiccup.

Keep it under 2%. Go higher and ISPs start thinking you're a spammer. Your reputation tanks. Recovery takes weeks. Not fun.

Here's what people miss though. Bounce rate is tied to how fresh your data is. Working off a list from six months ago? People changed jobs since then. Companies closed. Emails got killed. That's why email validation and deliverability matter so much.

Yarden, a Growth Leader, said it pretty clearly: "Focus on cleaning your data and figuring out the timing before you scale up. AI subject line tests are helpful, but data quality comes first."

He's right.

3. Spam Complaint Rate

Formula: (Spam Complaints / Emails Delivered) × 100

This one should worry you. Stay under 0.1%. That's the line. Go above it and ISPs start dumping your stuff straight to spam.

Why do people hit that spam button? You emailed someone who didn't expect it. Your subject line was misleading. There's no clear unsubscribe button. Basic stuff really. Follow CAN-SPAM compliance rules and avoid common cold email mistakes and you'll be fine.

Got contacts in Europe? GDPR applies. Don't try to wing it with international compliance. That never ends well.

4. List Growth Rate

Formula: ((New Subscribers – Unsubscribes – Bounces) / Total Subscribers) × 100

Your list is growing or it's dying. There's nothing in between. Every month you lose people to unsubscribes, bounces, and folks who just stop caring. The email list growth rate formula tells you if new sign-ups are keeping up.

Healthy growth is 2-5% a month. Lower than that? You're shrinking and probably don't even know it.

Your bounce rate depends on data freshness. Platforms like Scrap.io pull real-time business contacts from Google Maps. When a business updates their listing or website, you get that info right away. No more emailing people who left six months ago. Try 100 free leads with a 7-day trial and see what happens to your deliverability.

Engagement KPIs

Good. Your emails are landing. Now: is anybody doing anything with them? These email engagement metrics tell you if your content connects or just sits there.

5. Open Rate (+ Apple MPP Disclaimer)

Formula: (Unique Opens / Emails Delivered) × 100

Average email open rate: 43.46% per MailerLite's big benchmark study. Looks nice on paper right?

Problem is Apple Mail Privacy Protection broke this metric. Apple pre-loads email content. Triggers open tracking even when nobody opened anything. So that 43% is inflated. Maybe a lot.

Is open rate totally useless? No. If it drops 20% month-over-month, something changed. That's useful. But as a standalone number? Don't trust it. Pair it with CTR and CTOR.

6. Click-Through Rate (CTR)

Formula: (Total Clicks / Emails Delivered) × 100

This one actually measures action. Someone read your email AND clicked something. That's real. Average for 2026: 2.09% per MailerLite.

What is a good click rate for email marketing? Between 2-4% is solid. Above 4%? You're killing it. Below 1%? Something's seriously off. Your content, your offer, your targeting. Maybe all of it.

Omnisend found that personalized subject lines boost opens 10-14%. And Growth-onomics reported that segmented campaigns can double your CTR. Double. Not a small bump. Double.

7. Click-to-Open Rate (CTOR)

Formula: (Unique Clicks / Unique Opens) × 100

Okay so this might be the most useful email KPI right now. Why? It separates content quality from subject line performance. If someone opened AND clicked, your email content did its job.

Average CTOR: 6.81% per MailerLite. This number matters more now precisely because open rates are shaky.

What's the difference between CTR and CTOR? CTR counts clicks against all delivered emails. CTOR counts clicks against opened emails only. CTOR gives you a cleaner read on whether your actual email content is working.

8. Unsubscribe Rate

Formula: (Unsubscribes / Emails Delivered) × 100

Average: 0.22% from MailerLite. That's your email unsubscribe rate benchmark.

Some unsubscribes are fine. People filtering themselves out makes your list sharper. But sudden spikes? Bad sign. You probably changed frequency, shifted content, or just surprised people.

Keep it below 0.5%. Higher than that and you're burning your list down.

9. Forward/Share Rate

Formula: (Forwards or Shares / Emails Delivered) × 100

Super underrated. When somebody forwards your email they're saying: "This is good enough that someone else needs to see it." Free growth. Free word-of-mouth.

Nobody forwarding your stuff? Your content is fine but not share-worthy. Ask yourself honestly: would I send this to a coworker? If the answer's no, there's your problem.

10. Read Time / Engagement Time

How long are people actually spending on your emails? Most platforms track this now. It tells you if people are scanning and leaving or genuinely reading.

Short read time on a long email = boring content. Long read time on a short email = nailed it. Use this to figure out the right email length.

Conversion & Revenue KPIs

Opens are okay. Clicks are better. But we all know the real point. Revenue. Sales. Actual results. These email campaign metrics connect email to money.

Michal Leszczynski from GetResponse nailed it: "Conversion rate is the single most important KPI. It immediately answers whether a campaign lived up to expectations."

11. Conversion Rate

Formula: (Conversions / Emails Delivered) × 100

A conversion is whatever you want it to be. A purchase. A demo booking. A sign-up. A download. This bridges email activity and business results.

Industry averages go from 1-5% depending on your space. There's a pretty popular take on Quora that I keep coming back to: "While everyone else suggests tracking fluff metrics like open rate, there is only one metric you should use to measure success. And it revolves around what you wanted from the email."

That's it. Know what you want BEFORE you hit send.

12. Revenue Per Email (RPE)

Formula: Total Revenue from Campaign / Total Emails Sent

Revenue per email sent KPI. Simple math. Send 10,000 emails, make $5,000? That's $0.50 per email. Now you can compare campaigns fairly.

Campaign A makes $0.80 per email. Campaign B makes $0.15. Where do you put more budget? Easy call.

13. Revenue Per Subscriber

Formula: Total Email Revenue / Total Active Subscribers

Like RPE but per subscriber over time. Tells you what your average subscriber is worth. Feeds into how much you can spend to get new ones.

14. Email Marketing ROI

Formula: (Revenue from Email – Total Email Costs) / Total Email Costs × 100

The big number. How to calculate email marketing ROI? That formula right there. And the industry average is wild: $36-$45 returned for every $1 spent, per Litmus and Moosend.

No other channel does that consistently. But you only get those numbers if you're measuring properly and fixing what's broken.

15. Cost Per Acquisition (CPA) via Email

Formula: Total Email Campaign Cost / Number of Conversions

How much does one customer cost you through email? Add up platform fees, content time, list maintenance, data costs. Divide by conversions. Lower is better. Track monthly.

Cold Email & Outreach-Specific KPIs

This is the section most guides skip completely. Cold email KPIs are a different game. Different audience. Different rules. Different benchmarks.

If you're prospecting, booking meetings, opening doors – these three metrics matter most.

16. Reply Rate

Formula: (Replies / Emails Delivered) × 100

Cold email reply rate benchmark for good B2B: 5-10% per Instantly and Backlinko. Average cold email open rate is around 27.7% from InfraForge data. But opens don't pay the bills. Replies do.

Jake Jorgovan does B2B consulting. Targets CMOs with hyper-personalized cold emails. Heavy research on every contact. Tracks reply rates and meeting bookings like a hawk. Gets engagement rates way above average. Why? Every email shows he actually did his homework.

Then there's Ambition. Performance management SaaS going after VPs of Sales. They tested personalized emails against generic templates. Tracked opens, replies, meetings. The personalized version crushed generic on every metric. Every single one.

Personalization isn't a nice-to-have in cold email. It's the whole thing.

17. Meeting Booking Rate

Formula: (Meetings Booked / Emails Sent) × 100

For B2B people this is the metric that fills your pipeline. Good meeting booking rate from cold email: around 1-3%. Sounds small until you look at the deal values those meetings create.

And remember: 80% of sales need 5+ follow-ups. One email doesn't tell you much. Keep going.

18. Positive Reply Rate

Formula: (Positive Replies / Total Replies) × 100

Not every reply is a good reply. "Remove me" is a reply. "Not interested" is a reply. This KPI filters for replies that move things forward. Interest. Questions. Meeting requests.

SalesHandy documented how they optimized their cold outreach. Constant A/B tests on subject lines, CTAs, personalization. They measured positive responses specifically. Not just total replies. That distinction made all the difference.

Want results like these? Start with fresh leads. Scrap.io grabs real-time contacts from Google Maps. When businesses update their team pages or listings, you get current info right away. Fresh data = better reply rates, fewer bounces. Try 100 free leads with a 7-day trial.

Advanced & Strategic KPIs

These two take a longer view. They tie daily email performance metrics to big-picture value. Most marketers skip them. That's exactly why you shouldn't.

19. Subscriber Lifetime Value (LTV)

Formula: Average Revenue Per Subscriber × Average Subscriber Lifespan

What's a subscriber worth over their whole relationship with you? This changes how you think about acquisition, content, everything.

To'ak Chocolate works with Omnisend. Luxury chocolate brand. They found that 40% of their email revenue comes from automated campaigns. Welcome series mostly. By tracking engagement KPIs and building automated flows around them, they turned revenue around. Big time.

When you know a subscriber is worth $150 over their lifetime, spending $10 to get them is obvious. Without that LTV number, $10 feels expensive.

20. Email Attribution Revenue

Formula: Total revenue attributed to email touchpoints in the conversion path

Most people don't buy from a single email. They touch your brand across channels. Email Attribution Revenue tracks how much total revenue included email somewhere in the journey. Not just last-click.

Set up UTM tracking. Connect email platform to analytics. Use multi-touch attribution. It's not easy but it gives you the real picture.

2026 Email Marketing Benchmarks by Industry

Quick reference. B2B email marketing benchmarks by industry from MailerLite's 2025 analysis of 3.6 million campaigns and ActiveCampaign's 2026 data.

These are averages. Not targets. Your audience will do its own thing. Track your own numbers quarter-over-quarter. That's the real benchmark.

And yeah — open rates across every industry are inflated because of Apple MPP. Lean on CTR and CTOR for email click-through rate by industry comparisons that actually mean something.

How to Start Tracking Your Email KPIs Today

Twenty KPIs at once? That's too much. Don't try it. Here's a better way.

Week 1: The basics. Get delivery rate, bounce rate, CTR, and conversion rate set up. These four tell you most of the story. Your email platform probably tracks them already. You just need to look.

Week 2: Go deeper. Add CTOR, unsubscribe rate, and read time. Make a simple dashboard. A spreadsheet works. Nothing fancy.

Week 3: Follow the money. Set up UTM tracking. Start calculating RPE and ROI. This is where email goes from "I think it works" to "it makes us $X."

Week 4: Test and improve. Now you've got data. Use it. A/B test subject lines. Test send times. Segment your lists. Growth-onomics showed segmented campaigns double CTR. That's not a small win. That's massive.

For cold email, your outreach metrics live and die by data quality. If you're writing cold emails that get responses, send them to people who still work there. The YMCA figured this out after struggling with generic messages and a wrecked sender reputation. They switched to behavioral triggers and tagged contacts by engagement. Deliverability went up. Engagement went up. Everything improved.

Same idea if you're doing local prospecting. Better data in, better KPIs out. Simple as that.

And if your current cold email tools aren't tracking this stuff well enough, maybe upgrade.

FAQ

What are the most important email marketing KPIs?

Five essentials: delivery rate (did your emails arrive?), click-through rate (did anyone click?), conversion rate (did they do the thing you wanted?), bounce rate (is your list clean?), and email marketing ROI (was it worth the money?). These five cover the whole funnel from send to revenue.

What is a good email open rate in 2026?

Average is 37-43%. But open rates got unreliable since Apple Mail Privacy Protection. Apple pre-loads email content which inflates the numbers. Better to focus on CTR (aim for 2-4%) and CTOR (aim for 6-7%). Those measure real engagement that Apple can't fake.

How do you calculate email marketing ROI?

Formula: (Revenue from Email – Total Email Costs) / Total Email Costs × 100. Average return is $36-$45 per $1 spent per Litmus and Moosend. Make sure you count everything in costs: platform, content creation, list maintenance, data acquisition. Get an honest number.

What's the difference between CTR and CTOR?

CTR = clicks divided by all delivered emails. CTOR = clicks divided by opened emails only. CTOR is more reliable in 2026 because it shows you content quality without subject line noise. Low CTR but high CTOR? Your subject lines need work. Both low? Your content needs work.

What is the 80/20 rule in email marketing?

80% of your email content should give value. Education. Insights. Useful stuff. Only 20% should be direct sales. This keeps people engaged instead of annoyed. For KPIs, it also means most of your results come from a small percentage of campaigns. Find the winners. Figure out why they won. Do more of that.

How often should you review email marketing KPIs?

Weekly for campaign stuff: CTR, bounce rate, conversion rate. Monthly for bigger picture: ROI, subscriber LTV, list growth. Quarterly for comparing against industry benchmarks and adjusting strategy.

Final Thoughts

Twenty KPIs. Don't track them all on day one. That'd be nuts.

Pick the ones that match your biggest question. Emails not arriving? Deliverability KPIs. Getting opens but no clicks? Engagement metrics. Clicks but no revenue? Conversion numbers.

People who win at email in 2026 aren't sending the most emails. They're measuring the right things. And fixing what's broken. Week after week.

Email still returns $36-$45 for every dollar spent. That hasn't changed. But you only get that kind of ROI when you know which email performance indicators to watch and which to ignore.

Stop high-fiving over open rates. Start caring about conversions. And make sure the contacts you're emailing are still real people at real companies. Every KPI downstream falls apart when you're sending to outdated lists.

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