Email Marketing Metrics: Which Numbers Matter and How to Read Them

Your email dashboard shows open rates, click rates, delivery rates, conversion rates, unsubscribes, bounces, list growth, forwards, click maps and engagement scores. Most of it is noise. Act on the wrong number and you can spend weeks tuning subject lines to lift open rates while revenue doesn’t move.

This guide covers which metrics drive decisions, which ones mislead, what published benchmarks actually say (and why they disagree), and how to read campaign and automation reports without fooling yourself.

The Open Rate Problem

The biggest distortion in email analytics is that open rates no longer measure reading.

Apple launched Mail Privacy Protection (MPP) on iOS 15 and iPadOS 15 on September 20, 2021, and brought it to Macs with macOS Monterey. In Apple’s own words, it “prevents senders from seeing if you’ve opened the email message they sent you.” In practice, Apple loads remote content, tracking pixel included, through its own servers, so your platform can record an open for an email nobody looked at.

The scale is large. Litmus’s July 2026 client data, based on over a billion tracked opens, attributes 62.26% of opens to Apple’s mail clients, and Litmus notes that opens from users with MPP turned on “are not considered reliable opens.” MailerLite’s benchmark report says the same thing from the sender side: MPP automatically marks emails to Apple Mail as opened, so real open rates are lower than dashboards show.

Open rate still has some value as a relative signal. If one subject line gets 60% opens and another gets 35% on the same audience, something real is probably happening. The problems start when you compare your open rate to an industry figure or treat it as a measure of engagement.

The Metrics That Actually Matter

1. Click Rate (CTR)

What it is: Unique clicks divided by emails delivered.

Why it matters: Clicks take intent. A proxy server prefetching images doesn’t click links, and Apple says MPP doesn’t extend to links. Click rate tells you whether the content is relevant, the offer is compelling and the call to action works.

Benchmark: MailerLite’s 2025 data puts the median click rate at 2.09% across all industries, with industries ranging from 0.83% to 4.90%. Your own trend matters more than either number.

Its blind spot: It only counts people who clicked. Some loyal readers read every issue and rarely click.

What moves it: How well the offer fits the segment, how clear the CTA is, how many links compete for attention, and how long the email is.

2. Click-to-Open Rate (CTOR)

What it is: Unique clicks divided by unique opens. CTR measures interest across everyone who received the email; CTOR measures how well the body works for the people who opened.

Why it matters: It separates content performance from subject line performance. High opens with low CTOR means the subject line pulled people in and the body didn’t deliver. Low opens with high CTOR means the subject line is weak but the content converts.

The MPP catch: Inflated opens sit in the denominator, so your CTOR looks lower than it really is even when click behavior hasn’t changed. MailerLite’s 2025 median CTOR was 6.81%. Use CTOR to compare your own campaigns to each other, not as an absolute benchmark, and never against pre-2021 data.

3. Conversion Rate

What it is: The share of recipients who completed the action you wanted: a purchase, a trial signup, a booked call, a download.

Why it matters: This is the closest metric to business results, and every other metric is a proxy for it. A 60% open rate and a 5% click rate mean little if those clicks don’t convert.

Setting it up: Add UTM parameters to every link and connect your email tool to your web analytics, or use your email platform’s native ecommerce integration. Ecommerce-focused tools such as Klaviyo pull order data from the store and report purchases per email.

Conversion rates vary too much by industry, offer and list quality for a universal benchmark to be useful. Track your own and watch the trend. Attribution also gets complicated: if someone clicks an email and buys a week later through a search ad, different models will credit email differently.

4. Revenue Per Email

For ecommerce, revenue per email (total revenue attributed to a campaign divided by emails sent) cuts through most of the other numbers. If it rises over time, the program is improving. If it falls, find out why. Expect triggered flows like abandoned cart and post-purchase to earn far more per email than broadcasts, because they go to smaller, higher-intent audiences.

5. Spam Complaint Rate

What it is: The share of delivered emails that recipients mark as spam. Mailbox providers report complaints back to senders through feedback loops, and most email tools show the rate per campaign.

Why it matters: This is the danger metric. Google’s sender guidelines ask bulk senders to keep their user-reported spam rate below 0.1% and never let it reach 0.3%. The effect is graduated: Google says rates above 0.1% already hurt inbox delivery, and 0.3% or higher has an even bigger impact and makes a sender ineligible for mitigation. Yahoo’s sender requirements set the same 0.3% ceiling. One badly targeted campaign can push you into that range.

What to do: Stay well below 0.1%, and investigate before you send again if any campaign moves toward it. Google Postmaster Tools is free and shows your spam rate and domain reputation as Gmail sees them, data you can’t get anywhere else.

What causes spikes: Emailing people who forgot they signed up, importing a bought or rented list, a subject line or offer that feels deceptive, or suddenly sending much more often than usual.

6. Hard Bounce Rate

What it is: The share of emails rejected permanently: the address doesn’t exist, the domain is invalid, or the receiving server refuses your mail.

Why it matters: Hard bounces point to list hygiene problems, and repeatedly sending to dead addresses harms your sender reputation. Most platforms suppress a hard-bounced address after the first bounce. Confirm yours does.

What to do: Watch for a jump on any one send. The usual causes are an old import, a signup form without validation, or addresses that went stale while you weren’t sending. If bounces stay high, run the list through a verification service before the next campaign. Our email list cleaning guide walks through the process.

7. Engaged List Size and Net Growth

Total subscribers is a vanity number. A list of 50,000 sounds better than 8,000, but if 40,000 of them haven’t clicked anything in a year, you are paying to email people who don’t want your mail, and your complaint rate and deliverability pay for it too.

Track two things instead:

• Engaged list size: subscribers who clicked at least once in the past 90 days. Growth here is real growth.
• Net list growth: (new subscribers − unsubscribes − hard bounces) ÷ subscribers at the start of the month. A flat total can hide steady churn: 200 new subscribers a month may only be replacing the 200 who left.

If net growth is negative, list building needs to become a priority. Our list building guide covers specific tactics.

Metrics to Watch, Not Optimise

Unsubscribe Rate

A low unsubscribe rate isn’t automatically good news. Irritated readers can unsubscribe, mark you as spam, or ignore you. Ignoring you drags down engagement, and marking you as spam actively hurts deliverability. Unsubscribing is the polite option, and the one you should prefer.

MailerLite’s 2025 median unsubscribe rate was 0.22%, up from 0.08% in 2024. MailerLite puts the jump down to Gmail making it easier to unsubscribe without opening the email. A spike after one send says that message didn’t fit that audience. A rising trend across every campaign points to a relevance or frequency problem.

Open Rate, Read Directionally

Use opens to compare your own campaigns against each other: subject line tests, send-day tests, segment comparisons. The better judge for a subject line test is still clicks. If your platform lets you pick the A/B winner by click rate, do that.

What Published Benchmarks Say, and Why They Disagree

Benchmarks are useful for rough orientation and risky for precise goals. Look at how far three current sources are apart:

Source	Data	Open rate	Click rate
MailerLite	3.6M campaigns, Dec 2024 to Nov 2025, medians	43.46%	2.09%
ActiveCampaign	Customer campaigns, Jan 1 to Dec 10, 2025, incl. transactional	39.26%	6.21%
Mailchimp	All users, data as of December 2023	35.63%	2.62%

ActiveCampaign’s click rate is roughly three times the others because its figure includes transactional emails, which people click far more often. Each platform’s customer mix is different, and all of them count MPP opens. None of these is wrong, and none of them is your benchmark.

By industry, MailerLite’s 2025 data shows the highest open rates in religion (55.71%), hobbies (53.25%) and nonprofits (52.38%), and the highest click rates in legal (4.9%), manufacturing (4.22%) and media (4.1%). A 2.5% click rate is roughly typical in some industries and strong in others, so context matters more than the raw number. Our email marketing benchmarks article has the full industry breakdown.

How to Read Campaign Reports

Review each campaign 48 to 72 hours after sending, once most of the engagement has come in.

Compare it to your baseline. If your typical click rate is 3% and a campaign gets 1.2%, something went wrong: wrong segment, weak offer, broken link, confusing layout. If it gets 5.8%, work out why and repeat it. Keep separate baselines per segment; your engaged buyers will always beat your re-engagement segment.

Look at clicks by link. Click maps and link-level reports show which CTA drove behavior. If 90% of clicks went to one of three links, the other two are clutter. Simplify.

Read unsubscribes against the audience. One percent of your general list leaving after a promotion is a problem. One percent of a re-engagement segment leaving is expected; that’s what the campaign was for.

Check the client breakdown. If most of a segment opens in Apple Mail, its open rate means very little. Knowing your client split tells you how much of your “open rate” is real.

How to Read Automation Reports

Automated flows (welcome, abandoned cart, post-purchase, re-engagement) behave differently from broadcasts, so read them differently.

Volume is lower and rates are higher. A welcome email goes to someone who signed up minutes ago, so strong engagement is expected, not exceptional. Don’t compare flow emails to broadcast benchmarks.

Judge the flow, not each email. Evaluate an abandoned cart sequence on total revenue per person who entered it. The first email usually does most of the work and the later ones pick up stragglers, but they all count.

Audit flows quarterly. Automations run in the background and are easy to forget. Are they still sending? Are conversion rates holding? Does a welcome flow built two years ago still mention an offer that ended or a product you discontinued?

Set a Reporting Cadence

Analytics without a review rhythm is noise.

• Weekly (five minutes): Spam complaint rate, bounce rate, and anything odd in active flows. You’re looking for anomalies, not trends.
• Monthly: Click rate trend, unsubscribe trend, revenue per email if you sell, net list growth and engaged list size. Compare with the same month last year if you have the data.
• Quarterly: Audit automations, compare segments, check domain reputation in Google Postmaster Tools, and revisit your frequency and list hygiene.

A spreadsheet with four numbers per week (click rate, complaint rate, hard bounce rate and, for stores, revenue per email) tells you most of what you need to know.

How to Improve the Metrics That Matter

To improve click rate:

• Use fewer CTAs. One clear call to action beats three competing ones.
• Make sure the body delivers what the subject line promised. When they don’t match, clicks drop.
• Test link placement. A text link mid-paragraph sometimes beats a button at the bottom.
• Segment more tightly. A product email sent to people who showed interest in that category beats the same email sent to everyone. Our segmentation guide shows how.

To improve conversion rate:

• Check what happens after the click. A good email pointing at a weak landing page will always underperform.
• Test the offer itself. Sometimes a conversion problem is really a pricing, positioning or timing problem.

To protect your complaint rate:

• Run a re-engagement sequence on anyone who hasn’t clicked in 90+ days, and suppress non-responders before big campaigns.
• Don’t write subject lines the email doesn’t live up to.
• Make unsubscribing easy. A hard-to-find unsubscribe link pushes people to the spam button instead.

Which Tools Give You the Best Analytics

Klaviyo

Klaviyo is the standard for ecommerce reporting. It connects store data to email activity, so you see the revenue each campaign and flow generated, not just clicks. The free plan covers 250 active profiles and 500 email sends a month, and the Email plan starts at $20/month. The catch: the depth only pays off if you feed it ecommerce events, and the bill grows with your active profile count. For a newsletter or B2B program you’d use a fraction of it.

ActiveCampaign

ActiveCampaign includes campaign, automation and contact-level reporting, so you can see exactly what one contact received and clicked over time. Attribution and conversion tracking start on the Plus plan ($49/month billed annually for 1,000 contacts) and connect email activity to CRM deals, which helps B2B senders see how email influences pipeline. The Starter plan ($15/month billed annually) has basic reporting but caps automations at 5 actions each. ActiveCampaign’s pricing page lists annual rates only.

MailerLite

MailerLite has the clearest dashboard for anyone still building a reporting habit: opens, clicks, unsubscribes and bounces per campaign, laid out simply. Its free plan covers 250 subscribers and 2,500 emails a month, and Comfort starts at $12/month for 500 subscribers. It lacks Klaviyo’s revenue attribution, but for newsletters and early-stage businesses the basics are easy to act on.

For more options, see the advanced analytics feature page.

Where to Focus First

If you’re setting up tracking for the first time, start with three numbers: click rate, spam complaint rate and hard bounce rate. Together they tell you whether the content works, whether your list practices are safe, and whether the list itself is in good shape.

Once those are healthy, add conversion tracking through your web analytics or ecommerce integration, and then revenue per email.

Open rate will stay on your dashboard. Glance at it, but don’t let it make your decisions.

For the money side of these numbers, see our email marketing ROI guide. If a platform that makes acting on your metrics easier sounds useful, browse the best email marketing tools for automation or read our automation guide.

Sources

1. Apple — Use Mail Privacy Protection on iPhone — accessed 2026-10-05
2. Litmus — Apple Mail Privacy Protection for Marketers (September 20, 2021) — accessed 2026-10-05
3. Litmus — Email Client Market Share (July 2026) — accessed 2026-10-05
4. MailerLite — Email marketing benchmarks by industry — accessed 2026-10-05
5. ActiveCampaign — 2026 Email Marketing Benchmarks — accessed 2026-10-05
6. Mailchimp — Email Marketing Benchmarks — accessed 2026-10-05
7. Google — Email sender guidelines — accessed 2026-10-05
8. Yahoo — Sender best practices — accessed 2026-10-05
9. Google Postmaster Tools — accessed 2026-10-05
10. Klaviyo — Pricing — accessed 2026-10-05
11. ActiveCampaign — Pricing — accessed 2026-10-05
12. MailerLite — Pricing — accessed 2026-10-05