|
Key Takeaways
|
|
Open rate can’t carry your reporting anymore. Average open rates have more than doubled since 2021 while click rates stayed in a narrow band, so clicks, conversions and revenue give a truer read on whether an email landed. Delivered and inboxed are different numbers. Delivery rates now average above 99 percent, but mail filed to spam still counts as delivered, so inbox placement shows what subscribers can see. The metrics that matter most need data from outside email. Conversion rate, revenue per recipient and ROI all depend on connecting clicks to orders, returns and repeat purchases. Your own trend line is the benchmark that counts. Averages shift by market, sector and message type, so compare each campaign type against its own history first. |
Email marketing metrics are the measures that show how an email program performs – from whether messages reach the inbox to whether they produce revenue. A KPI is the smaller set of those metrics tied to a specific business objective, so click-through rate might be a diagnostic metric for the CRM manager and the headline KPI for whoever owns the welcome journey.
Imagine a CRM team at a home and garden retailer sent a product launch email on a Tuesday morning. By lunchtime the dashboard shows a 34 percent open rate and a 3.1 percent click-through rate, and the head of ecommerce asks one question: did it sell anything?
Most email dashboards can’t answer that without three other tabs and a spreadsheet. Open rate confirms a tracking pixel loaded, and click-through rate confirms someone tapped a link. Neither confirms whether that tap turned into a purchase, a sign-up or a return visit.
The 13 metrics I’m going to highlight are grouped into sets based on the burning question they answer:
- Are your emails arriving?
- Do people care?
- Is any of it connecting to revenue?
- Is your audience growing or shrinking?
I’ve given you each one with its own formula, a sourced benchmark where reliable data exists, and the context that metric-by-metric lists tend to leave out. Let’s dive in.
Email marketing metrics at a glance
Use unique delivered emails, unique opens and unique clicks wherever a formula calls for them, so the numbers stay comparable across campaigns.
The sections below cover how to read each one, and where its number can mislead you.
Deliverability metrics: are your emails arriving?
Abraham Lincoln reportedly said: “Give me six hours to chop down a tree and I will spend the first four sharpening the axe.”
Translated to marketing that’s: “One bad list import undoes months of sender reputation work.”
It happens a lot. The marketing team at a homeware brand imports 12,000 contacts from a trade show and adds them to the next campaign. Delivery rate drops from 97 percent to 84 percent as invalid addresses bounce and, over the next three sends, more of the mail that did get through starts landing in spam folders.
So, before engagement or revenue, the first question is whether your emails reach the inbox at all, and these four metrics tell you:
1. Delivery rate
What it measures: The percentage of sent emails accepted by the recipient's mail server.
Formula: (Emails delivered ÷ Emails sent) × 100
Benchmark: In the DMA Email Benchmarking Report 2026 (UK, 2025 data from six email service providers), delivery rate reached a record 99.2 percent across all email, with retail also at 99.2 percent.
B2B sat lower at 95.6 percent, recovering from 90.7 percent the year before.
"Delivered" only means a server accepted the message. An email filed straight to spam still counts, which is why delivery rate needs inbox placement next to it.
A delivery rate below 95 percent usually points to one of three things:
– Authentication gaps, with SPF, DKIM or DMARC records misconfigured or missing
– A deteriorating sender reputation, often from high bounce or complaint rates on previous sends
– List hygiene issues, where you're sending to addresses that no longer exist
Each of those compounds over time. Treat a sudden drop after a list import as a warning about every campaign that follows.
2. Inbox placement rate
What it measures: The percentage of delivered emails that land in the inbox rather than the spam folder.
Formula: (Emails reaching the inbox ÷ Emails delivered) × 100, estimated through seed-list testing or panel data
Mail servers don't report where they file a message, so there's no industry-wide inbox placement figure to compare against the way there is for delivery rate. Your own rate over time, split by mailbox provider, is the benchmark to track.
Any shortfall here stays invisible in your delivery rate, and it depresses every engagement and revenue metric further down the funnel.
Inbox placement tends to fall when mailbox providers tighten enforcement or when complaint rates creep up. Check it by mailbox provider, because a program can place well with one and poorly with another.
3. Bounce rate
What it measures: The percentage of sent emails rejected by the recipient's mail server, split into hard and soft bounces.
Formula: Hard bounce rate = (Hard bounces ÷ Emails sent) × 100. Soft bounce rate = (Soft bounces ÷ Emails sent) × 100.
Benchmark: The DMA Email Benchmarking Report 2026 recorded average hard bounce rates of 0.04 percent and soft bounce rates of 0.022 percent in 2025 (UK). Soft bounces ticked up from 0.017 percent the year before as Google and Yahoo enforced their sender requirements. Hard bounces are permanent failures, such as an address that doesn't exist. Remove those addresses immediately, because repeated sends to them damage reputation fast.
Soft bounces are temporary: a full inbox or a server issue. An address that soft-bounces across several consecutive sends should be suppressed before it becomes a reputation problem.
Even a clean list doesn't stay clean. People change jobs, abandon inboxes and switch providers, so bounce rate creeps up without regular list hygiene even when acquisition is healthy.
4. Spam complaint rate
What it measures: The percentage of recipients who marked your email as spam.
Formula: (Spam complaints ÷ Emails delivered) × 100
Benchmark: Google's email sender guidelines ask senders to keep their user-reported spam rate below 0.1 percent and never let it reach 0.3 percent. Bulk senders above 0.3 percent aren't eligible for mitigation from Google's deliverability support.
Complaint rate has always affected sender reputation, and since February 2024, when Google and Yahoo began enforcing their bulk sender requirements, the thresholds have been explicit. Exceed them and your emails can be throttled or blocked across your sending domain, well beyond the campaign that caused it.
A difficult unsubscribe process is one of the most common causes. If opting out means logging in, confirming twice or navigating a preference center, some recipients will hit the spam button instead, and that complaint follows you. Google now requires bulk senders (those sending close to 5,000 or more messages a day to Gmail addresses) to offer one-click unsubscribe in marketing and subscribed messages.
Engagement metrics: do people care?
Once emails are arriving, the next question is whether anyone cares. These three metrics measure attention, with one important caveat: privacy features have made some of them less reliable than they were five years ago.
5. Open rate
What it measures: The percentage of delivered emails where the tracking pixel loaded.
Formula: (Unique opens ÷ Emails delivered) × 100
Benchmark: The DMA Email Benchmarking Report 2026 recorded an average open rate of 43.5 percent across all email in 2025, with B2C at 55.0 percent, retail at 49.2 percent and travel at 34.8 percent (UK). Read the context below before comparing your own number.
Since September 2021, Apple Mail Privacy Protection has preloaded tracking pixels for users who turn it on, whether or not they open the email, and other mailbox providers prefetch content too. The DMA data shows the effect: average open rates sat around 19 percent from 2016 to 2021, then climbed to 43.5 percent by 2025, while click rates stayed between 1.5 and 2.5 percent throughout.
Open rate still has uses. It works for relative comparisons, such as subject line A against subject line B with the same audience on the same send, and a sudden drop across all campaigns can flag a deliverability problem.
It also matters for automation. If any journey branches on “opened” versus “didn’t open,” privacy-driven opens can send people who never read the email down the engaged path. Branch on clicks, site visits or purchases where you can, and annotate reporting where privacy-influenced opens can be identified within your consent and governance rules.
6. Click-through rate (CTR)
What it measures: The percentage of delivered emails where a recipient clicked at least one link.
Formula: (Unique clicks ÷ Emails delivered) × 100
Benchmark: The DMA Email Benchmarking Report 2026 recorded a record unique click rate of 2.5 percent across all email in 2025, with B2C at 2.2 percent and travel at 1.2 percent (UK). Retail fell from 2.0 percent to 1.0 percent, despite posting one of the highest open rates in the report.
With open rate compromised, CTR is a more dependable engagement signal. A click requires a deliberate action, and a preloaded pixel can’t produce one.
CTR varies widely by email type, so benchmark each type against its own history. Transactional emails such as order confirmations and shipping updates typically out-click promotional campaigns, and a triggered cart abandonment email reaches people with very different intent from a full-list newsletter. Split it by device as well, because a layout that works on desktop can push the call to action out of sight on a phone.
The levers for improving CTR tend to sit in content and design:
- One primary call to action instead of three competing links
- Content relevant to the specific segment receiving it
- The primary link placed where subscribers see it without scrolling
- Personalization that goes beyond first-name merge tags
Relevance is the lever with the most room. In SAP’s Global Engagement Index 2026, 58 percent of consumers said most marketing emails they receive aren’t relevant to them.
7. Click-to-open rate (CTOR)
What it measures: The percentage of people who opened the email and then clicked a link.
Formula: (Unique clicks ÷ Unique opens) × 100
Benchmark: The DMA Email Benchmarking Report 2026 recorded an average CTOR of 6.2 percent across all email in 2025, with B2C at 3.8 percent, travel at 3.6 percent and retail at 2.1 percent (UK).
CTOR answers a specific question: of the people who opened, how many found the content compelling enough to act? If open rate is high and CTOR is low, the subject line is earning the open and the email body is losing the click.
CTOR uses opens as its denominator, though, and privacy features have inflated that denominator for a large part of most audiences. B2C email shows the problem clearly: a 55 percent open rate alongside a 3.8 percent CTOR in 2025, a fall the DMA report's commentary attributes largely to proxy server opens.
For most teams, CTR is now the safer primary metric. CTOR keeps its value for content testing, such as two email designs sent to the same segment, where the inflation is consistent across both variants and cancels out.
Conversion and revenue metrics: is email driving business results?
The question behind every revenue metric is attribution: can you connect an email click to a purchase, a loyalty sign-up or a contract? If your engagement solution has no access to what happens after the click, your revenue metrics are educated guesses.
8. Conversion rate
What it measures: The percentage of clickers who completed a defined action, such as a purchase, sign-up or booking.
Formula: (Conversions ÷ Unique clicks) × 100
"Conversion" covers a lot of ground. A newsletter sign-up, a product purchase and a program enrollment represent very different levels of commercial intent, so define what counts for each campaign type and keep the definition fixed.
The attribution window matters just as much. A purchase three days after a click may count under a seven-day window and disappear under a 24-hour one, so agree the window before comparing campaigns or teams.
Expected conversion rates also shift across lifecycle stages:
– Welcome series: high intent, because the subscriber has just opted in
– Cart abandonment triggers: variable, and often the highest revenue per send in the program
– Win-back campaigns: lower conversion rates, and disproportionately valuable when they work because you're recovering a lapsed customer
Comparing those three against one conversion benchmark would reward the wrong campaigns.
9. Revenue per recipient
What it measures: The average revenue generated for each email delivered.
Formula: Total email-attributed revenue ÷ Emails delivered
Revenue per recipient normalizes across list sizes and send volumes. Sending 500,000 emails that generate $25,000 is a very different result from sending 50,000 emails that generate the same amount. Some teams divide by emails sent instead, which is fine as long as you pick one version and stick to it. Report total attributed revenue next to it, so leadership sees email's absolute contribution as well as its efficiency.
It gets most useful when you compare campaign types. A monthly newsletter can post strong opens and almost no direct revenue while a browse abandonment trigger with modest opens earns far more per recipient, and both have a role in the program.
Revenue per recipient requires access to transaction data as well as click data. If your reporting stops at the click and picks up again in a separate ecommerce dashboard, the figure is an estimate built on assumptions about what happened in between.
Revenue per subscriber
Revenue per recipient measures a single send. Its program-level counterpart, revenue per subscriber, shows what your email audience is worth over time: total email-attributed revenue divided by total active subscribers over a period. A list of 200,000 active subscribers generating $400,000 in quarterly email-attributed revenue has a revenue per subscriber of $2.00. If that number rises, the program is getting more valuable. If it stays flat while the list grows, you’re adding subscribers who don’t buy.
10. Email marketing ROI
What it measures: The return on investment from your email program.
Formula: ((Revenue from email − Cost of email program) ÷ Cost of email program) × 100
Headline ROI figures circulate widely, and most of them depend on an attribution model you can't see. Under last-touch attribution, an email that was the final touchpoint before a sale gets full credit, while multi-touch attribution splits that credit across every channel involved.
The same campaign can report a very different ROI under each model. Track assisted conversions alongside last-touch results, and where the stakes justify it, run a controlled holdout: withhold the campaign from a random slice of the audience and measure the difference in purchases.
The cost side matters too. Most ROI calculations include software and creative production, and fewer include the team time spent on strategy, segmentation, testing and analysis, which changes the denominator meaningfully.
A reliable ROI figure depends on full-funnel visibility. When campaign data sits next to order data, loyalty status and repeat purchase behavior, ROI rests on real transactions. SAP Engagement Cloud connects campaign performance with customer and business data, giving teams more context for measuring what happens after the click.
List health metrics: is your audience growing or shrinking?
A high-performing campaign sent to a shrinking list is a declining asset. These three metrics show whether your email program is sustainable.
11. Unsubscribe rate
What it measures: The percentage of recipients who opted out after a specific send.
Formula: (Unsubscribes ÷ Emails delivered) × 100
The DMA Email Benchmarking Report 2026 recorded an average unsubscribe rate of 0.10 percent in 2025 (UK), back down from a spike to 0.38 percent in 2024. Your own per-send average is the more useful reference point.
A rising unsubscribe rate alongside stable click rates isn't always a problem. Disengaged subscribers opting out improves list quality and, over time, deliverability.
The concern is a spike after a specific campaign, or one that coincides with a change in send frequency, content direction or targeting. An unsubscribe is also far preferable to a spam complaint, which is why an easy one-click opt-out protects the rest of your program.
12. Net list growth rate
What it measures: The net rate at which your reachable list grows after losses.
Formula: ((New subscribers − Unsubscribes − Bounced addresses removed − Complaint removals) ÷ Total list size) × 100
Your list loses addresses every month whether you notice or not. If net growth isn't outpacing that churn, your reachable audience declines regardless of how well individual campaigns perform.
Track active subscriber rate alongside it: subscribers who clicked, bought or visited within a set window, divided by the total list. A growing list with a shrinking active share is adding people who never engage. The reverse figure, inactive subscriber share, sizes the audience your re-engagement campaigns need to reach.
Purchased and rented contacts damage deliverability, so healthy growth comes from value exchanges:
– Content worth subscribing for
– Post-purchase opt-ins
– Loyalty program enrollment
Each of those gives a subscriber a reason to keep opening.
13. Re-engagement rate
What it measures: The percentage of previously inactive subscribers who interact with a re-engagement or win-back campaign.
Formula: (Subscribers who re-engaged ÷ Inactive subscribers targeted) × 100
Re-engagement rate tells you how much of your lapsed audience is recoverable, and when to stop trying and clean the list instead. Fix the definition of "inactive" first, whether that's 90 days without a click or 180 days without a purchase, so the rate means the same thing every quarter.
Measuring email across the customer journey
Campaign metrics tell you how a send performed. Journey metrics tell you whether email is moving customers from one stage to the next, and they’re the ones leadership cares about.
SAP’s Global Engagement Index 2026 describes that shift directly: engagement measured by opens, clicks and conversions gives way to engagement measured by retention, loyalty and lifetime value. The practical version is pairing each journey stage with a leading indicator you can see quickly and an outcome that proves the business result.
Leading indicators move within days, so review them weekly with the teams running each journey. Outcomes such as repeat purchase and customer lifetime value move over months and belong in monthly and quarterly reporting.
Email rarely drives an outcome alone. A replenishment email, an app notification and a paid media retargeting ad might all touch the same repeat purchase, so assess email alongside those channels and use holdout groups where you need to know what email added on its own.
To see how brands pair each stage with a measured result, look at these lifecycle email campaigns from PUMA, AO and John Frieda.
Customer lifecycle management that segments by stage natively makes this breakdown possible without manual tagging or CSV exports.
How to read your email metrics without misleading yourself
A metric only means something against the right comparison: last month, a different campaign type or an industry average. Three habits keep that comparison honest.
Compare each campaign type with its own history
A cart abandonment email and a monthly newsletter are different products, and comparing their CTRs is like comparing close rates on inbound leads with outbound cold calls. Build baselines per campaign type, and use industry benchmarks such as the DMA’s as a secondary check, adjusted for market, sector, audience source, season and message type.
Be wary of drawing global conclusions from single-market data. The DMA figures in this guide describe UK sending, and performance in other markets can differ. For sector-by-sector detail, see our breakdown of email engagement rate benchmarks.
Watch the trend across months
A single campaign’s open rate is noise, while a three-month decline in CTR across your triggered emails is a signal. Most dashboards make individual campaign results easy to see and program-level trends hard to find, so set up the trend view deliberately.
Read related metrics together
Most problems show up as a combination of numbers moving at once. These five patterns come up repeatedly:
Once you’ve found the likely cause, change one thing, measure the result against the same baseline, and record what you learned so other journeys can apply it.
Connect email data to what happens after the click
Conversion rate, revenue per recipient and ROI all require data from outside email. With access to order data, loyalty status and service interactions, your metrics tell a business story; without it, you’re reporting on clicks and hoping they correlate with revenue.
Getting there is as much a data question as a marketing one, so bring in your IT, data and operations teams early. The foundations to agree between them:
- One customer identity across email, web, app, commerce and service records
- Shared event definitions, so “purchase” and “active” mean the same thing in every report
- An agreed attribution window and a named owner for each source of truth
- Consent records and access controls that hold up across every region you send to
With those in place, split reporting in two: a short executive scorecard of outcome metrics each month, and a deeper practitioner view of deliverability and engagement each week.
Measuring email alongside the rest of the business with SAP Engagement Cloud
The core email marketing metrics haven’t changed much in a decade. The context has: privacy features have weakened opens, stricter sender requirements have raised the bar for reaching the inbox, and budget conversations now expect proof of revenue impact.
SAP Engagement Cloud treats email as one channel within customer engagement, alongside web, app, SMS and in store. It connects real-time customer insights with operational signals such as orders, service events, loyalty milestones and inventory, so the same data that drives a personalized journey across channels also measures what that journey produced.
For SAP customers, integration with SAP ERP and commerce systems brings business data into that picture directly. When your engagement data connects with what happens elsewhere in the business, email marketing metrics become the basis for decisions about budget, journeys and channels.
Email marketing metrics Frequently Asked Questions
Click-through rate, conversion rate, revenue per recipient and inbox placement matter most for most programs. Together they show whether emails arrive, get attention and produce revenue. Open rate is still worth tracking for subject line tests, but privacy features make it unreliable as a headline KPI.
Start with the business objective for each campaign or journey, then choose a leading indicator such as CTR and an outcome metric such as revenue per recipient or repeat purchase rate. Compare results against your own history for the same campaign type, and connect email data to transaction data so revenue figures reflect what customers bought.
CTR divides unique clicks by delivered emails, while CTOR divides unique clicks by unique opens. CTR shows overall engagement; CTOR isolates how well the content converts people who opened. Because privacy features inflate opens, CTOR is best reserved for comparing content variants sent to the same audience.
Unlike opens, clicks, conversions, revenue, unsubscribes, spam complaints and inbox placement don't rely on the tracking pixel that Apple Mail Privacy Protection preloads. Open rate remains useful for relative comparisons on the same send. Any automation that branches on opens should move to clicks or site behavior where possible.
It depends on market, sector and message type. In the DMA Email Benchmarking Report 2026, UK email averaged a 99.2 percent delivery rate, 43.5 percent open rate, 2.5 percent click rate and 6.2 percent click-to-open rate in 2025. Your own trend line for each campaign type is a more reliable target than any cross-industry average.
Review deliverability and engagement metrics weekly, because problems compound quickly. Journey outcomes such as repeat purchase and lifetime value move more slowly and suit monthly or quarterly reporting, with a short outcome-focused scorecard for executives.
About the author
Ellie Quacquarelli is a Strategic Consultant & Team Lead at SAP Engagement Cloud in London. With 10+ years of experience, she helps businesses develop customer-centric CRM strategies and measure ROI in an era of evolving email privacy. Passionate about enhancing customer experiences, Ellie specializes in driving meaningful audience connections across marketing channels, working closely with brands to optimize engagement and long-term retention.
