Email Marketing Metrics You Should Track Every Month
Introduction
Most email marketers are drowning in data but starving for insight. They check open rates after every send, celebrate high numbers, worry about low ones, and never quite understand why their email program is or is not driving revenue. The problem is not a lack of metrics. It is tracking the wrong metrics, or tracking the right ones without knowing what to do with them.
In 2026, 392.5 billion emails are expected to be sent every day. With inboxes this crowded, small differences in performance can create meaningful differences in leads, revenue, or retention. Designmodo
Email remains the most profitable owned marketing channel available. The industry average email marketing ROI sits at $36 to $42 for every dollar spent. It is the highest-returning digital marketing channel across sectors. Ecommerce Fastlane But that return is only possible when you know which signals to watch and what action to take when those signals shift.
This guide covers every email marketing metric you should review monthly, what each one actually tells you, the 2026 benchmarks to measure against, and the specific actions to take when numbers fall outside healthy ranges.
Why Monthly Metric Reviews Matter
A single campaign's performance is rarely meaningful on its own. Metrics only tell useful stories over time. A monthly review rhythm forces you to ask the right questions: Is our open rate trending up or down? Is our unsubscribe rate creeping higher? Are our automated flows outperforming our broadcast campaigns? Are we growing the list faster than we are losing it?
Performance is no longer just about what happens immediately after a send. It is about how recipients perceive and interact with a brand over time. That aligns with how mailbox providers now filter inboxes. Engagement is not just measured. It is interpreted. And the signals they prioritize increasingly resemble relationship health, not campaign performance. MarTech
Monthly reviews also create the accountability that weekly or daily checks cannot. You see trends that individual campaigns obscure, and you have enough data to make decisions that are based on patterns rather than noise.
Metric 1: Email Deliverability Rate
What It Is
Deliverability rate measures the percentage of your emails that successfully reach recipients' inboxes rather than bouncing or landing in spam. This is the foundation that every other email metric sits on.
Deliverability is the foundation of all email performance. Low inbox placement caps your open rate, CTR, and revenue regardless of content quality. Benchmark: Aim for 95 percent plus deliverability. Anything below 90 percent signals issues with authentication, list quality, or sender reputation. Pushwoosh
Why You Must Track It Monthly
A deliverability problem that goes unnoticed for six weeks can take months to fix. Email service providers like Gmail and Outlook score your sender reputation continuously based on engagement patterns, spam complaints, and bounce rates. Once your reputation degrades, even emails to engaged subscribers start landing in spam.
What to Do When It Falls
If your deliverability rate drops below 95 percent, audit your list immediately. Remove hard bounces and inactive subscribers who have not opened or clicked in 180 or more days. Check that your domain authentication records including SPF, DKIM, and DMARC are properly configured. Review your recent content for spam trigger words. If you have been sending to large cold lists, pause and warm up your sending domain properly before resuming at full volume.
Metric 2: Bounce Rate
What It Is
Bounce rate tracks the percentage of emails that failed to deliver, split into two categories. Hard bounces are permanent failures caused by invalid email addresses or nonexistent domains. Soft bounces are temporary failures caused by full inboxes or server issues.
High bounce rates damage sender reputation and reduce future deliverability. Hard bounces should be removed from your list immediately. Pushwoosh
Benchmarks
A healthy hard bounce rate is below 0.5 percent per campaign. A soft bounce rate below 1 percent is considered acceptable. If either figure exceeds these thresholds consistently, list quality is your primary problem.
What to Do When It Rises
Hard bounces above 0.5 percent indicate you have invalid addresses on your list. This happens when you have not cleaned the list recently, when subscribers entered fake addresses at sign-up, or when contacts have changed employers and their corporate email no longer exists. Use an email validation service to clean your list quarterly. Add real-time email validation to your sign-up forms so that invalid addresses are caught before they enter your database.
Metric 3: Open Rate
What It Is
Open rate is the percentage of delivered emails that were opened by recipients. It is calculated by dividing the number of unique opens by the number of delivered emails.
The median email open rate across all 3.6 million campaigns in our dataset was 43.46 percent. Email open rates by industry ranged from 30.1 percent to 55.71 percent. MailerLite
The Apple Mail Privacy Protection Problem
Open rate is the most widely tracked metric in email marketing and also the most distorted one in 2026. Apple Mail Privacy Protection automatically marks emails sent to Apple Mail clients as opened. This means real open rates are lower than the metrics you see in your dashboard. MailerLite
With users having the option to block email tracking pixels, open rates may no longer provide a precise measure of actual opens. This devaluation emphasizes the importance of shifting focus towards more reliable metrics such as click-through rates and click-to-open rates. Salesforce
How to Use Open Rate Correctly
Despite its limitations, open rate remains a useful directional metric. Use it to track trends over time, not to measure true interest or content performance. Designmodo If your open rate drops 10 percentage points over three months, that trend is meaningful even if the absolute number is distorted. It signals that your subject lines are losing effectiveness, your sender name has become less trusted, or your emails are landing in promotional tabs rather than primary inboxes.
Optimize open rate through subject line testing, preview text optimization, and send time personalization. Send Time Optimization identifies the best hour to send emails within the next 24 hours based on each subscriber's past opens and clicks, increasing the chance of your message landing in the inbox when they are most likely to engage. Insider
Metric 4: Click-Through Rate (CTR)
What It Is
Click-through rate measures the percentage of all email recipients who clicked at least one link in the email. It is calculated by dividing the number of unique clicks by the number of delivered emails.
A good CTR for email marketing typically falls in the range of 2 percent to 5 percent, although industry benchmarks may vary. Factors such as business size, industry, and the type of emails being sent are all a consideration. Salesforce
The average email click rate across all 3.6 million email marketing campaigns was 2.09 percent. Click rates across industries ranged from 0.83 percent to 4.90 percent. MailerLite
Why CTR Matters More Than Open Rate
A click indicates that the reader found the message relevant enough to take action, which makes CTR more meaningful than open rate for evaluating content performance. Designmodo Unlike open rate, CTR is not distorted by privacy protection changes. A click is a definitive, trackable human action.
Low CTR despite healthy open rates means your email content is not delivering on the promise of your subject line, your call to action is unclear or weak, or your offer is not compelling enough to motivate action. Each of these is a solvable problem with a specific fix.
How to Improve CTR
Place your primary call to action above the fold so it is visible without scrolling. Use a single dominant CTA rather than multiple competing links. Write CTA button text that describes the specific action the reader will take rather than generic phrases like "Click Here" or "Learn More." Test different email content angles and formats to identify what your specific audience responds to.
Metric 5: Click-to-Open Rate (CTOR)
What It Is
Click-to-open rate measures the percentage of people who opened the email and then clicked a link. It is calculated by dividing unique clicks by unique opens.
Generally, a CTOR above 20 percent is considered strong. However, the ideal CTOR can differ based on specific circumstances. Salesforce
CTOR is a useful metric because it can show how engaging your email content is. A low open rate with a high CTOR suggests that the people who open your emails find the content relevant. In this situation, increasing your open rate would likely boost overall campaign performance. MailerLite
How to Use CTOR for Diagnosis
CTOR isolates the quality of your email content from the performance of your subject line. If your CTOR is strong but your overall CTR is low, the problem is upstream: your subject lines are not attracting enough opens. If your CTOR is weak despite a healthy open rate, your content or CTA is the problem. This diagnostic clarity makes CTOR one of the most actionable metrics in your monthly review.
Metric 6: Conversion Rate
What It Is
Conversion rate measures the percentage of email recipients who completed a desired action after clicking through from your email. This could be a purchase, a free trial sign-up, a demo booking, a download, or any other goal action defined for that campaign.
Conversion rate is what ultimately connects your email program to business outcomes. High open rates and click rates that do not lead to conversions mean your landing pages, offers, or post-click experience are breaking down somewhere in the funnel.
Tracking It Properly
Conversion tracking requires connecting your email platform to your website analytics through UTM parameters. Every link in every email should carry UTM tags that identify the source, medium, and campaign name. This lets you see in Google Analytics 4 or your e-commerce platform exactly which email campaigns generated what revenue and at what conversion rate.
Benchmark your conversion rate by campaign type. Welcome sequence emails typically convert at much higher rates than broadcast campaigns. Abandoned cart emails typically outperform both. Understanding the expected conversion rate for each email type prevents you from comparing unlike campaigns against each other.
Metric 7: Revenue Per Email (RPE) and Revenue Per Recipient (RPR)
What They Are
Revenue Per Email measures the total revenue attributed to a campaign divided by the number of emails sent. Revenue Per Recipient measures the same but per individual recipient reached.
Flows generated $0.94 per recipient versus $0.04 for campaigns, a 22-fold gap at the portfolio level. Flows consistently drive higher average order value across the portfolio. BS&Co
Why This Separates Serious Programs From Average Ones
RPE and RPR cut through the noise of engagement metrics and connect directly to what the business cares about. Click rate is the metric everyone watches. It is also the one that lies to you the most. Across 11 e-commerce brands and 7.5 million emails, portfolio-wide campaign click rate was 0.46 percent. Those same brands generated $619,257 in email-attributed revenue, representing 25 percent of total store revenue. Click rate says we are failing. Revenue says we are not. BS&Co
Track RPE and RPR monthly by campaign type and compare automated flows against broadcast campaigns. This comparison consistently reveals that automated sequences, such as welcome flows, abandoned cart emails, and post-purchase sequences, generate dramatically higher revenue per recipient than one-time campaign sends.
Metric 8: Unsubscribe Rate
What It Is
Unsubscribe rate is the percentage of recipients who opted out after receiving an email.
The median unsubscribe rate across all campaigns was 0.22 percent. MailerLite A rate above 0.5 percent per campaign consistently is a warning sign that your content is not meeting subscriber expectations or that you are sending too frequently.
What Unsubscribes Actually Tell You
A healthy unsubscribe rate is not zero. People change their interests, change jobs, and change email habits. Some churn is natural and healthy. The concern is when the rate spikes or trends upward over multiple campaigns.
Spike analysis is particularly useful. When a single campaign generates significantly higher unsubscribes than your baseline, examine what was different: was the subject line misleading, was the offer irrelevant to a large segment of the list, or was the email sent to a segment that had not been contacted in a long time?
Metric 9: Spam Complaint Rate
What It Is
Spam complaint rate measures the percentage of recipients who marked your email as spam rather than unsubscribing. This is one of the most damaging metrics for sender reputation.
Gmail and Outlook treat complaint rates above 0.1 percent as a warning threshold and above 0.3 percent as grounds for bulk filtering or blocking. Keep your monthly spam complaint rate below 0.08 percent.
A campaign with decent click rates can still hurt deliverability if it generates enough complaints or unsubscribes. The disaffection index combines unsubscribes, complaints, and bounces into a single metric that answers a question most dashboards ignore: How quickly are you burning through your audience? MarTech
How to Keep Complaint Rates Low
Make the unsubscribe option impossible to miss. When subscribers cannot easily unsubscribe, they report as spam instead. Set up Google Postmaster Tools and Microsoft SNDS to monitor complaint rates directly from mailbox providers rather than relying solely on your email platform's reporting. Use preference centers that let subscribers choose email frequency and content type rather than forcing a binary subscribe or unsubscribe decision.
Metric 10: List Growth Rate
What It Is
List growth rate measures how fast your subscriber list is growing after accounting for new subscribers minus unsubscribes and bounces. A positive growth rate means you are adding more subscribers than you are losing. A flat or negative rate means your program is slowly dying.
Positive, steady growth is the goal. Flat or negative growth usually signals acquisition-retention imbalance or low opt-in quality. To improve, optimize opt-in timing. Ask for email after a meaningful action such as a first purchase, feature use, or account creation, and offer value at signup such as exclusive content, discounts, or early access. Pushwoosh
How to Track It
Calculate list growth rate monthly using this formula: new subscribers minus unsubscribes and bounces, divided by the total list size at the start of the month, multiplied by one hundred. A growth rate above 2 percent monthly is healthy for most businesses. Below 1 percent warrants examining both acquisition and retention strategies.
Metric 11: Email Marketing ROI
What It Is
Email marketing ROI measures total revenue generated from email divided by total spend on email including platform costs, creative production, and staff time.
A strong email marketing ROI is considered $36 return per $1 spent, representing 3,600 percent ROI, while top performance can reach up to $70 or more return per $1 spent. Pushwoosh
Automated emails drive 37 percent of all email-generated sales despite making up only 2 percent of total sends. Ecommerce Fastlane This single data point illustrates why monthly ROI tracking should always separate campaign sends from automated flows. The two have fundamentally different economics.
How to Calculate It Monthly
Add up all revenue attributed to email in your analytics platform. Add up all email-related costs including platform subscription, content creation time, and any agency fees. Divide revenue by cost. Compare your monthly ROI to the industry benchmark of $36 to $42 per dollar. If you are below benchmark, examine whether your automated flows are set up and functioning correctly, as they drive the largest share of email revenue for most programs.
Metric 12: Flow Versus Campaign Performance
The Most Underused Monthly Comparison
Flows generated $0.94 per recipient versus $0.04 for campaigns, a 22-fold gap at the portfolio level. BS&Co This gap exists because automated flows reach subscribers at high-intent moments: when they just signed up, when they abandoned a cart, when they have not purchased in 90 days. Campaigns reach everyone regardless of intent.
Every month, compare three metrics between your flows and your campaigns: revenue per recipient, conversion rate, and average order value. If your flows are dramatically outperforming campaigns, that signals you should be investing more in building and optimizing automated sequences rather than increasing campaign send frequency.
Building Your Monthly Email Dashboard
Tracking these metrics is only useful if you review them in a structured way. Build a simple monthly dashboard with twelve columns, one for each month, and one row for each metric. At the start of each month, populate last month's numbers. Note any significant changes from the previous month. Identify the one or two metrics that changed most and prioritize investigating those first.
Compare your metrics to the benchmark range, not just the average. This tells you where you are performing as expected and where improvement will have the biggest impact. Suppose your open rate is close to the industry average, which suggests your subject lines and sender reputation are working reasonably well. Your click-through rate, however, is noticeably lower than the benchmark. That gap tells you where to focus. Instead of trying to improve opens, prioritize clearer calls to action, tighter messaging, or better alignment between email content and landing pages. Designmodo
The most important question your monthly dashboard should answer is not "how did we do?" It is "what do we do differently next month?" Every metric should lead to a specific action, not just an observation.
Conclusion: Measure What Moves the Business
The email metrics that matter most are the ones connected to outcomes your business actually cares about: revenue, customer retention, list health, and return on investment. Open rate is a tool for trend analysis, not a measure of success. CTR and CTOR tell you about content quality. Conversion rate and RPR tell you about business impact. Deliverability, bounce rate, and spam complaints protect the infrastructure that everything else depends on.
Email marketing ROI in 2026 is one of the most cited metrics in e-commerce and one of the most misread. Most brands know email performs well. However, some do not know how much this channel is working for them. Ecommerce Fastlane
Track all twelve metrics every month. Review them in the same order each time. Identify the one or two that most need attention and make those your priority for the next 30 days. Do this consistently and your email program will not just generate data. It will generate decisions, improvements, and compounding returns month over month.