Email marketing metrics are the data points that tell you whether your email campaigns are working — and where they are not. They cover everything from how many people open your emails and click your links, to how many bounce, unsubscribe, or convert into customers.
Email remains one of the highest-ROI marketing channels available — delivering an average return of $36 for every $1 spent, according to Litmus. But that return is not automatic. It depends on consistently monitoring the right metrics, understanding what they signal, and making informed optimisations over time.
This guide covers the seven most important email marketing metrics to track in 2026, how to calculate each one, what it tells you about campaign and deliverability health, and how to improve performance — including how Ortto's email analytics tools make monitoring and optimisation faster.
Key stat: Email marketing delivers an average ROI of $36 for every $1 spent — the highest of any digital marketing channel. (Litmus, 2025)
How to benchmark your email performance
Before diving into specific metrics, it's worth understanding how to set meaningful benchmarks. Many marketers reach for industry-wide average open rates or click rates published by email platforms — but this approach has a significant flaw.
As Travis Hazlewood, Head of Email Deliverability at Ortto, has noted: open rate averages for the same industry can differ by as much as 20% between different reporting platforms — an alarming variance when the lower figure is already at 20%. On top of that, the rise of security software that auto-clicks links to check for threats means engagement stats themselves are less reliable than they appear.
The more useful approach is to benchmark against your own historical performance. Review your current 30-day stats and compare them to the previous 30–90 days. This gives you a baseline that is specific to your audience, your sending frequency, and your content — and makes it far easier to spot meaningful trends or anomalies that warrant investigation.
Key stat: Industry email benchmarks can vary by up to 20% between platforms for the same sector — making internal historical comparisons a more reliable performance standard. (Ortto, Head of Email Deliverability)
7 email marketing metrics to monitor and improve in 2026
Email performance is not about any single number — it's about the relationship between metrics. A strong open rate combined with a low click rate points to subject line success but content failure. A high click rate with low conversion suggests a landing page problem, not an email problem. Track all seven metrics below, but always read them together.
1. Open rate
What it is: The percentage of delivered emails that are opened by recipients. It is the first engagement signal in the email funnel and a primary indicator of subject line effectiveness and sender trust.
How to calculate:
(Number of opens ÷ Number of emails delivered) × 100 = Open rate %
What it tells you:
Open rate is most valuable when tracked consistently over time rather than assessed campaign by campaign. A sustained decline in open rates — especially across multiple campaigns — is often an early warning sign of deliverability issues, such as increased spam filtering or reduced sender reputation. At a campaign level, it reflects the strength of your subject line, preview text, and 'from' name.
How to improve it:
Low on a specific campaign: Test a new subject line, update your preview text, or experiment with sending from a named person rather than a brand alias. Personalisation tokens in subject lines (e.g. first name) can lift open rates meaningfully. Declining trend across campaigns: Audit your sending practices. A declining trend signals a deliverability issue — check your bounce rate, spam complaint rate, and whether you're sending to unengaged contacts.
Ortto tip: Ortto's AI subject line tester analyses millions of real-world send results to predict open rate performance before you send. Use it to compare subject line variants and pick the strongest one — without running a full A/B test.
2. Click-through rate (CTR)
What it is: The percentage of delivered emails in which at least one link was clicked. It measures how many of your total recipients took action on your email — regardless of whether they opened it first.
How to calculate:
(Number of clicks ÷ Number of emails delivered) × 100 = CTR %
What it tells you:
CTR is the primary indicator of email content and CTA effectiveness. Not all emails need a high CTR — purely informational or transactional emails may not include clickable CTAs. But for campaigns with a clear goal (event registration, product promotion, content download), a low CTR signals that the content, design, or offer is not compelling enough to drive action.
How to improve it:
Use audience segmentation to ensure content is relevant to each recipient — the most common driver of low CTR is sending generic content to a broad list. Apply the inverted triangle design principle to guide the reader's eye toward your CTA. Shorten and clarify your copy so the value of clicking is immediately obvious. Test CTA button colour, placement, and copy in A/B sends.
Ortto tip: Ortto's email analytics show click heatmaps at the individual link level — so you can see exactly which links in your email are being clicked, and which are being ignored. Use this to refine your layout and CTA placement with every send.
3. Click-to-open rate (CTOR)
What it is: The percentage of people who opened your email and then went on to click a link. Unlike CTR, CTOR isolates email content performance by removing the open rate variable.
How to calculate:
(Number of clicks ÷ Number of opens) × 100 = CTOR %
What it tells you:
CTOR is a more precise diagnostic metric than CTR. Because it only counts people who opened the email, a low CTOR tells you that the content itself — not the subject line, deliverability, or send time — is failing to drive action. This makes it particularly useful when your open rates are healthy but CTR is low: CTOR confirms whether the problem sits inside the email or before it.
How to improve it:
Apply all standard CTR improvement tactics: tighten your copy, sharpen your CTA, and test design layout. With CTOR, you can be confident the issue is inside the email rather than in your subject line or deliverability — so optimise content first. Also consider whether the email's value proposition matches the expectation set by the subject line: a mismatch between what you promised in the subject and what you delivered in the email is a common CTOR killer.
Ortto tip: Track CTOR alongside CTR in Ortto's campaign reports to quickly identify whether underperformance is a pre-open or post-open problem — then target your optimisation effort precisely.
4. Unsubscribe rate
What it is: The percentage of email recipients who opt out of your email list after receiving a campaign. It is a key list health indicator and a signal email service providers use when evaluating sender reputation.
How to calculate:
(Number of unsubscribes ÷ Number of emails delivered) × 100 = Unsubscribe rate %
What it tells you:
A high unsubscribe rate is not just a content problem — it's a deliverability risk. Email providers like Gmail factor unsubscribe signals into spam classification. If your unsubscribe rate trends upward over time, your sender reputation will suffer, and future campaigns are more likely to land in spam. A healthy unsubscribe rate is generally considered to be below 0.2% per campaign.
How to improve your unsubscribe rate:
Auditing your email processes and campaigns to ensure you are adhering to email deliverability best practices will go a long way to helping improve your unsubscribe rates — and preventing them from getting too high in the first place.
These checkpoints are the best place to start:
Get consent - ensure every audience member you are sending to has opted in. Not just to receive emails from your brand as a whole, but to receive the specific type of email you are sending. Preference centers are a great way to give your audience control over what they receive, and to manage audiences.
Engage meaningfully — Use audience segmentation, personalization, compelling copy and design to send useful, helpful information to your subscribers.
Be human — earn your audience’s trust by being as authentic and personal as possible. Appeal to their interests with engaging, natural language, rather than trying to “game” the inbox for attention.
List hygiene is another important part of reducing unsubscribes. Ensure you’ve got an automated reengagement or sunset campaign firing in the background to keep your audiences healthy, and consider using additional engagement filters (e.g. subscribers who have opened an email at least once in the last 30 days) on large sends to avoid sending to subscribers who are no longer interested in your brand, product or service.
5. List growth rate
Like an unsubscribe rate, list growth rate is displayed as a percentage to give you an understanding of your list health overall.
How to calculate a list growth rate:
First, you will need to know the total number of net new subscribers. To calculate this, take the total number of gained subscribers and subtract the total number of unsubscribed addresses and email bounces.
Divide this total number of net new subscribers by the total number of subscribers on your list, then multiply by 100 to get a percentage.
What a list growth rate tells you:
Email list growth rate is more of an indication of your general marketing activities, than your email specifically, though some subscribers could be gained from existing subscribers who forward or recommend your emails.
The rate shows you how quickly your list is growing. A growing list is nearly always a good thing — unless you’ve acquired emails through bad practices (like list buying) that go on to cause your unsubscribe rates to skyrocket. If you’ve acquired your subscribers through smart marketing and every individual has consented to receive your emails, steady, continuous, list growth is something to be celebrated.
How to improve your list growth rate:
It’s important to remember that slow, steady growth of truly interested, opted-in, engaged subscribers will always outperform quick growth from list buying or other harmful practices.
If you do have growth goals, start by making it easy for interested leads, customers, or website browsers to subscribe to your email list. To do this, check that there are easily identifiable forms in key areas of your site and that each one has an engaging hook to inspire subscribers to take action. Use reCAPTCHA or double-verification (or both!) to keep spam out, and to build an audience of people who have consented to receive emails from your business.
If list growth is a goal, consider what kind of engaging content you could offer via email to bring new subscribers in. For example, you could create an email course that drip-feeds information over a month or two, or you could send a newsletter that appeals to your audience’s interests. Once the new offering is ready, promote it through organic and paid channels or partnerships to drive growth. Later, you could create incentives for subscribers who share the content with a friend — this will form a growth loop that runs in the background to keep list growth rate steady.
6. Conversion rate
What it is: The percentage of email recipients who complete the specific action your campaign was designed to drive — a purchase, registration, booking, form submission, or other defined goal.
How to calculate:
(Number of conversions ÷ Number of emails delivered) × 100 = Conversion rate %
What it tells you:
Conversion rate is your most direct measure of campaign ROI — but only for campaigns where a clear conversion action exists. Transactional emails, brand awareness sends, and long-form nurture sequences are not well-suited to conversion rate measurement. For performance-led campaigns (promotional offers, event registrations, free trial sign-ups), conversion rate is the definitive metric of success.
How to improve it:
Diagnose underperformance by working backwards through the funnel. Low open rate → subject line or deliverability issue. Good opens, low clicks → content or design problem. Good clicks, low conversions → landing page problem. Use A/B testing at each stage to isolate variables. Ensure your email and landing page have message match — the offer and language should be consistent from inbox to conversion.
Ortto tip: Ortto's analytics connect email campaign performance to downstream conversions — so you can see the full attribution chain from email send to purchase, and calculate true revenue generated per campaign.
7. Email delivery rate
What it is: The percentage of sent emails that were successfully accepted by the recipient's mail server. It is the foundational metric that all other email metrics depend on — you cannot be opened, clicked, or converted if you are not delivered.
How to calculate:
(Number of emails delivered ÷ Number of emails sent) × 100 = Delivery rate %
What it tells you:
Delivery rate tells you what proportion of your emails did not bounce. A hard bounce occurs when an email address is invalid or does not exist. A soft bounce is temporary — usually a full inbox — and less concerning. A declining delivery rate is one of the clearest early warnings of a sender reputation problem: mail servers are increasingly rejecting your messages, which typically means your domain or IP has been flagged for spam-like behaviour.
How to improve it:
Review your bounce log after every send to identify patterns — typos, invalid addresses, spam-reported domains, or duplicate sends. Remove hard bounces immediately and investigate soft bounce patterns. Longer-term, protect your sender reputation by authenticating your sending domain (SPF, DKIM, DMARC), maintaining good list hygiene, and avoiding spam-trigger behaviours like purchased lists, misleading subject lines, or sudden volume spikes.
Ortto tip: Ortto's email deliverability dashboard surfaces bounce trends, delivery rate by campaign, and flags anomalies that may indicate a sender reputation issue — giving you the data you need to act before a deliverability problem compounds.
How Ortto helps you monitor and improve email performance
Ortto's email analytics are built to give marketing teams a complete, real-time view of all seven metrics above — in a single dashboard, without needing to stitch together data from multiple tools.
Campaign-level reporting: Open rate, CTR, CTOR, conversion rate, unsubscribe rate, bounce rate, and revenue attribution — all in one place.
Click heatmaps: See exactly which links in your email are being clicked, so you can optimise layout and CTA placement.
Trending charts: Track open rate and click rate over time to spot declining trends before they become deliverability problems.
Audience segmentation filters: Break down performance by audience segment, campaign type, or sending frequency to find what works for each part of your list.
AI subject line tester: Predict open rate performance before you send, based on millions of real-world data points.
Deliverability dashboard: Monitor bounce rate, spam complaints, and delivery trends with alerts for anomalies.
→ See Ortto's email analytics in action — Book a demo
Frequently asked questions
What are email marketing metrics?
Email marketing metrics are quantitative measures that track the performance of email campaigns. The most important ones are open rate, click-through rate (CTR), click-to-open rate (CTOR), unsubscribe rate, list growth rate, conversion rate, and email delivery rate. Together they provide a full picture of campaign health — from inbox placement through to revenue generated.
What is a good email open rate in 2026?
Industry averages vary significantly by sector and platform, making them an unreliable benchmark. A more useful approach is to compare your current 30-day open rate against your own previous 30–90 day performance. As a rough guide, open rates above 20% are generally considered healthy for B2B, and above 15% for B2C — but your own historical baseline is the more meaningful benchmark.
What is the difference between CTR and CTOR?
Click-through rate (CTR) is calculated as a percentage of all delivered emails. Click-to-open rate (CTOR) is calculated as a percentage of opened emails only. CTR gives you a measure of overall campaign engagement. CTOR isolates whether your email content — independent of your subject line or deliverability — is compelling enough to drive clicks. Use both together: a low CTR with a healthy CTOR suggests a pre-open problem (subject line, sender name, or deliverability). A low CTOR alongside a healthy open rate points to a content or design problem inside the email.
What is a good unsubscribe rate for email marketing?
A healthy unsubscribe rate is generally considered to be below 0.2% per campaign. Rates consistently above 0.5% are a warning sign that your list is receiving irrelevant content, your sending frequency is too high, or your subscribers did not truly consent to receiving your emails. Beyond the list health implications, high unsubscribe rates can negatively impact your sender reputation with email providers like Gmail and Outlook.
What causes a high email bounce rate?
Hard bounces are typically caused by invalid or non-existent email addresses — common sources include typos at sign-up, purchased lists, or contacts who have changed their email address. Soft bounces are usually temporary (full inbox, server outage) and less concerning. A rising hard bounce rate is a sender reputation risk and should be addressed immediately by removing invalid addresses and auditing your list acquisition practices.
How does email deliverability differ from email delivery rate?
Email delivery rate is a hard metric — the percentage of emails accepted by the recipient's mail server. Email deliverability is a broader concept that describes the likelihood of your emails reaching the inbox (rather than spam or promotions folders). You can have a high delivery rate (emails are being accepted) but poor deliverability (emails are landing in spam). Both matter, and Ortto's deliverability dashboard tracks signals for both.
How can I improve my email marketing metrics?
The most impactful improvements are typically: (1) Segmentation — sending more relevant content to smaller, targeted audiences consistently outperforms broad list sends. (2) List hygiene — removing unengaged or invalid contacts protects your sender reputation and improves all metrics. (3) Subject line optimisation — testing subject lines using an AI tool like Ortto's subject line tester can meaningfully lift open rates. (4) Content and design — ensuring your email copy is clear, the CTA is prominent, and the value of clicking is immediately obvious. (5) Send time optimisation — testing different send days and times to find when your audience is most likely to engage.
What email analytics does Ortto provide?
Ortto's email analytics cover all seven core metrics — open rate, CTR, CTOR, unsubscribe rate, list growth rate, conversion rate, and delivery rate — alongside click heatmaps, trending charts, revenue attribution, and a deliverability dashboard. Metrics can be filtered by audience segment, campaign type, or time period, making it straightforward to identify performance patterns and act on them.
Final word
Email marketing metrics are not just a reporting exercise — they are your most direct line of sight into what is working, what is not, and where to focus your optimisation effort next. The teams that consistently outperform on email are not the ones sending the most — they are the ones monitoring their metrics most carefully and making smart, data-driven adjustments over time.
Ortto's email analytics platform is built to make that monitoring fast and actionable — surfacing the right data at the right level of detail, so you spend less time in spreadsheets and more time improving performance.
