Recent stats show email ROI is $36 for every $1 spent. Spoiler alert: This isn’t true for everyone, especially those who neglect email testing tools.
We’ll illustrate.
Let’s say your marketing team emails 15,000 trial users who may want your product’s annual plan, which costs $504.
At a 30% open rate, you’ll have 4,500 potential customers. Unfortunately, because your team didn’t test the email, they discovered it didn’t optimally display for your Outlook clients.
If 10% of your trial users use Outlook, that means there are email rendering issues for 450 people. Factor in a 30% conversion rate, and that leaves you with 135 potential lost customers who never clicked your call to action (CTA). Put simply, you lost $68,040 (135 x $504) in potential revenue by not testing your email.
Avoiding unexpected rendering problems is one area where email testing tools shine. When you conduct email testing, you also prevent issues with grammar and spelling, broken email design, image display, and the dreaded spam trap, which hampers email deliverability.
In this post, we highlight the key factors to consider when leveraging email testing tools. We also put together 19 email testing tools that keep email rendering challenges at bay, help your emails evade spam folders, and ultimately allow you to drive revenue for your business.
Factors to consider when using email testing tools
To maximize the ROI of your email marketing strategy, it’s crucial to follow best practices when utilizing email testing tools. Here’s a breakdown of key considerations:
Test one element at a time: Focus on testing individual elements or variables in your email, such as the subject line, CTA, or layout. This approach allows you to accurately measure the impact of each component.
Use A/B testing: Create two variations of your email and test them on smaller audience segments. This helps you identify the better-performing version before rolling it out to your entire list.
Optimize subject lines: Your subject line is the first thing recipients see, so it must grab their attention. Experiment with different lengths, tones, and personalization to determine what drives higher open rates.
Preview before sending: Use email testing tools to preview how your email appears on various platforms (e.g., Gmail, Outlook) and devices (desktop, mobile, tablet). Ensuring proper rendering enhances the recipient’s overall experience.
Check load times: Test the loading speed of your emails, especially if they are heavy on images or video. Slow load times can frustrate readers and negatively impact engagement.
Validate CTAs and links: Double-check all links and CTAs to ensure they direct recipients to the correct pages and function properly. Broken links can lead to lost opportunities.
Leverage analytics: After sending your emails, analyze metrics like open rates, click-through rates, and conversions. Use this data to identify areas for improvement and refine your future email campaigns.
19 useful email testing tools for better performance
Pre-send spam testing, integration with 20+ apps, email, phone, and chat support, email preview of 100+ email clients, automated quality assurance and testing of email elements
Unlimited email previews, spam or deliverability checks, full content checking of links, images, and spelling, commenting access, email and chat support
Integrates with 40+ apps, unknown results are free, 24/7 customer support, IP address geolocation, inbox placement test, blacklist monitoring, 18 validation tools, multiple API keys, email server test
12,000+ real inboxes, email reputation monitoring, email monitoring dashboard, live blacklists and DNS checkups, email warm up for multiple email service providers
$25 per email account per month for one to five email accounts
Visual editor with HTML attributes and CSS modification support, API access (for enterprise users), report segmentation, multivariate testing, email split test
Free to $1174 per month (plus extra fee for additional contacts)
API access, win rate reporting, email split testing, collaboration within the Optimizely platform, knowledge base, technical, community, and academy support
Provides recommendations to fix technical problems with subject line, scannability, length, readability, subject line sentiment, identifying spam words, and more
Provides recommendations to fix technical problems with subject line, scannability, length, readability, subject line sentiment, identifying spam words, and more
Free
Email preview and spam testing tools
With over 300,000 potential renderings for any given email, there’s a wide range of differences in how a message can appear on different email clients. The same applies to email on desktop and mobile devices. This is where email preview tools work their magic.
Luckily, you can also use these tools for spam tests and ensure your email lands in your recipient’s inbox. A spam email test refers to the process of checking whether an email is flagged as spam by various email providers. Email spam tests involve using tools to analyze your email’s content, sender reputation and compliance with spam filters to improve deliverability.
Here are some excellent email preview and spam testing tools worth checking out:
Litmus is one of the best email automation testing tools used by small to enterprise-level organizations.
With Litmus, you can preview your email’s appearance on 100+ popular email clients like Outlook, Apple Mail, Gmail App, Samsung Mail, etc. And with the Litmus Spam Testing feature, you can evaluate your email against spam filters and receive notifications if your email is blocklisted or if you incorrectly set up your DMARC record.
Email features of Litmus
Pre-send spam testing
Integrates with 20+ apps
Email, phone, and chat support
Email preview of 100+ email clients
Automated quality assurance and testing of email elements like broken links, alt text and loading speed
Litmus pricing
Seven-day free trial
Basic plan: From $79 for 1,000 email previews every month for one full user
Plus plan: Up to $199 for 2,000 email previews every month for up to five full users
Mailtrap’s email preview works by analyzing your HTML and CSS and listing all issues it finds. Unlike Litmus, you can’t generate a preview for each email client, but you can identify common red flags among popular clients like Gmail and Outlook.
Besides Mailtrap’s preview and spam testing functionalities, an excellent email testing feature is the ability to conduct all email tests on a fake server, meaning the probability of unintentionally sending test emails to your email subscribers is zero.
Email features of Mailtrap
Spam testing
Access to Mailtrap API
Detailed information about email headers
Safe email testing with a fake SMTP server
Priority support on all plans except the free plan
Mailtrap pricing
Access to a free plan
Five other pricing options, ranging from $14.99 for the individual plan to $399.99 for the enterprise plan every month
Email on Acid is a top email testing tool used by marketers, developers, and enterprise companies like Toyota, The New York Times, and IBM. With Email on Acid, you can preview your email’s appearance on 90+ email clients and devices.
Plus, Email on Acid tests your message against 23 popular spam filters. The outcome? You gain insights on deliverability issues and fix them before pressing your send button.
Features of Email on Acid
Unlimited email previews
Spam or deliverability checks
Full content checking of links, images, and spelling
Commenting access on email previews for team collaboration
Email and chat support. Dedicated account rep on all plans, except The Basics plan
Designers, marketers, and developers use Preview My Email to assess their email appearance on over 54 clients. Preview My Email allows you to test emails by uploading your saved HTML code, copy-pasting your email, sending your email to a special Preview My Email inbox, or submitting your email via an API.
With Preview My Email, you can identify and fix spam issues as this tool checks your original IP against over 50 of the most common industry blacklists.
Features of Preview My Email
Advanced HTML editor
Unlimited email previews
Variable email spam and inbox testing depending on your plan
Pricing of Preview My Email
Seven-day free trial
Standard plan: $25 per month for one user
Business plan: $45 per month for one user
Professional plan: $160 per month for 10 users
Enterprise plan: $399 per month for 10 users
Email testing tools for deliverability
Writing great marketing emails that get opened, read, and acted on is one thing; ensuring the deliverability of the email is another. Before checking out the email deliverability tools, here’s a quick video on what you can do to make email delivery seamless.
SendForensics is an advanced email deliverability suite that uses multiple AI insights to gauge an email’s ability to reach your recipient’s inbox. This tool measures your email’s quality by evaluating it against global filtering-systems/ISPs, including human recipients.
Adding SendForensics to your email toolbox allows you to monitor your sending infrastructure, email content (including links), IPs, domains, and other things that can impact deliverability. As a bonus, this testing tool has email preview functionality.
Features of SendForensics
Email client preview testing
Live inbox placement testing
Predictive deliverability score
DMARC compliance verification
Blacklist and whitelist monitoring
Email content analysis and optimization
Infrastructure analysis and optimization
ISP (Internet Service Provider) reputation analysis
AI-driven insights of email content, sending infrastructure, and reputation
GlockApps is a comprehensive email deliverability solution that provides inbox insights, DMARC analytics, bounce tracker, IP reputation monitoring, and free spam testing.
Using GlockApps gives you access to uptime monitoring of your IP, website, SPF, DKIM, and DMARC records. Monitoring these helps secure your email reputation, maintain email health, and improve website conversions. On top of these, the free spam checker allows you to track your email’s destination (inbox, promotion, and spam folders) after you hit send. With this, you fix all deliverability challenges so you have an optimum conversion rate.
GlockApps features
Bounce analytics
Email spam tests
DMARC messages
Email template editor
IP reputation monitoring
GlockApps pricing
Access to a free account
Essential plan: From $79 per month for one user
Growth plan: From $99 per month for 10 users
Enterprise: From $129 per month for 20 users
You can also create a custom plan
Email automation testing tools for verifying invalid addresses
Sending emails to invalid addresses causes them to bounce back unopened. One reason for email bounce is invalid email addresses; and with increased bounce frequency comes increased hits to your reputation, making your future bulk emails appear like spam.
With these tools for verifying email addresses, you can permanently clean your list and nip this challenge in the bud.
ZeroBounce is one of the popular email verification tools that can validate your email list with a high-level of accuracy. Whether you want to clean a list of 100, 1,000, or 10,000 subscribers, this tool takes from seconds to some minutes to purge your list of invalid email addresses.
Besides email verification, ZeroBounce has intuitive email validation APIs that automate and assess the quality of your contacts at the point of capture. Also, ZeroBounce has functionalities for email deliverability tests and real-time blacklist monitoring.
ZeroBounce features
Integrates with 40+ apps
Unknown results are free
24/7 customer support
IP address geolocation
Inbox placement test
Blacklist monitoring
18 validation tools
Multiple API keys
Email server test
ZeroBounce pricing
ZeroBounce operates pay-as-you-go and monthly pricing models. For instance, the cost of validating 2,000 emails is $18 on pay-as-you-go. You also have access to 100 free monthly validations. Or you can have a monthly subscription from $39 per month.
Clearout is a great email verification tool with similar features like ZeroBounce. Like ZeroBounce, this tool stands out because it validates a subscriber’s email from the point of capture.
So whether you intend to capture emails via your website, exit pop-ups, WooCommerce checkouts, surveys/polls, chatbots, and newsletters, with Clearout, you can verify emails before they make it to your list. This prunes your list of invalid subscribers from the get-go, limits the chances of hard bounces, and improves deliverability.
Also, Clearout cleans your list of email duplicates, has spam detection algorithms, and verifies if your recipient’s mailbox can accept new emails.
Clearout features
Gibberish check for identifying random email addresses
Integrates with 100+ apps
Duplicate email removal
Greylisting verification
Blacklist monitoring
Spam trap detection
Simple API
Clearout pricing
Like ZeroBounce, Clearout operates pay-as-you-go and monthly pricing models. For instance, the cost of validating 5,000 emails is $35 on pay-as-you-go. Or you can consider a monthly subscription from $14 per month. You also have access to 100 free monthly validations.
NeverBounce is another excellent email verification tool with features similar to Clearout.
This tool provides real-time email verification, and it analyzes and verifies small to large lists. The best part? You can automate list cleaning by connecting your email provider to NeverBounce, meaning your email list will always be accurate and you’ll have peak deliverability.
Features of NeverBounce
API access
Custom list tagging
Bulk list email cleaning
Automated list cleaning
Integrates with 80+ apps
Real-time email validation
NeverBounce pricing
NeverBounce operates pay-as-you-go and monthly pricing models. Let’s say you have 5,000 emails to validate. That’ll cost $49 monthly or $40 on pay-as-you-go. You also have access to a free trial.
Email warm-up tools for improved deliverability
If you have a new email or one you haven’t used in a while, warm it.
Warming your email helps you establish a reputation for your IP and this prevents your email from landing in spam folders. While you can warm emails manually, an effective way to achieve similar results in less time is by using email warm-up tools. Here are some of them:
Lemwarm is one of the best email warm up tools that helps you wave goodbye to spam folders.
The tool operates by progressively sending and engaging with small amounts of personalized emails, depending on your email domain’s age. Best part? Rather than send and respond to emails using fake accounts, Lemwarm exchanges emails with its 20,000+ people from over 100 countries. The result? Your sender reputation is high and your emails reach your recipients’ primary inboxes.
Features of Lemwarm
Real people, no fake accounts
Warms up any email domain
25+ years domain age range
Email deliverability booster
Lemwarm pricing
Lemwarm offers a limited free plan, with pricing reaching up to $99 based on the selected tiers.
This intelligent email warm up tool is great for incrementally sending and engaging with emails and placing those that land in spam and promotion folders in the primary inbox. Besides that, MailReach exchanges emails with multiple email service providers, keeping your reputation high with Gmail, Outlook, etc.
Plus, its intuitive dashboard gives insights on your warm-up status, allowing you to know where emails from your campaigns will end up.
MailReach features
12,000+ real inboxes
Email reputation monitoring
Email monitoring dashboard
Live blacklists and DNS check-ups
Email warm up for multiple email service providers
MailReach pricing
Starter plan: $25 per email account per month for one to five email accounts
Scale plan: Starts at $19.50 per email account per month for over six email accounts. The pricing reduces with more email accounts to warm.
Powerful email marketing, minus the headaches
Email marketing plugs directly into your CRM data, so you can create highly targeted audience segments, track the impact of your emails in real-time, and manage all your communications out of a single tool. Get started for free!
As a popular AI-based email warmer, Folderly identifies, solves, and maintains all issues related to email deliverability. With Folderly, you can easily set up, track, and monitor your email warm up progress.
Furthermore, Folderly provides other email marketing solutions like email deliverability audit, email placement test, and it has an SPF Generator.
Folderly features
Automatically generated senders
GPT-3 powered interactions
Email warm up dashboard
Integrates with 10 apps
Email placement test
Folderly pricing
Folderly has a single pricing for its email warm up feature and that’s $49 per month
AutoWarmer is another powerful email warming tool like the others on this list.
One of its perks is the availability of a free-forever plan. While the free plan is great if you’re on a budget, it also limits your access to only warming inboxes on Gmail/Outlook/SMTP. You’d need to upgrade to a paid plan to use functionalities like the warm-up deliverability report.
Conducting A/B tests is an excellent way to assess the effectiveness of email elements like your subject line, body copy, personalization, CTA, and more.
A/B tests work by first deciding on one specific element to test, the number of versions to test, and your sample size. Done right, these A/B email automation testing tools won’t only increase your open rate, but increase your conversions.
VWO is a popular A/B testing tool that global brands use to test not just emails, but also web pages, apps and products. This tool can A/B test any element of your email campaign and measure the performance of the best variant.
Although this tool has multivariate testing functionality for evaluating multiple elements at once, it’s an email marketing best practice to test one element at a time.
VWO features
Visual editor with HTML attributes and CSS modification support
API access (for enterprise users)
Integrates with 40+ apps
Report segmentation
Multivariate testing
Email split test
VWO pricing
VWO has a limited free version, but prices can reach up to $1174 per month (plus extra fee per additional contacts)
Optimizely is another excellent A/B testing tool for testing elements of your email. Like VWO, Optimizely does multivariate analysis and has a suite of digital experience tools for ecommerce, websites, content management, and marketing planning.
Features of Optimizely
API access
Win rate reporting
Email split testing
Integrates with 180+ apps
Collaboration within the Optimizely platform
Knowledge base, technical, community, and academy support
Optimizely pricing
Optimizely pricing is undisclosed. You’ll have to contact their sales team if their Grow, Accelerate, or Scale plan interests you.
Mailchimp is a well-known email marketing tool with A/B email testing functionality. With Mailchimp, you can select the list segment for your campaign, pick the variable you want to test, set the percentage of recipients for the test, and determine the parameter for the winning variant.
Premium users also have access to multivariate testing for three variables and up to eight combinations.
Mailchimp features
A/B testing
Multivariate testing
Advanced segmentation
Integrates with 200+ apps
Knowledge base, email, live chat, and phone support
Mailchimp pricing
Email testing access is unavailable in the free plan
Essentials plan: $13-$350 per month depending on number of contacts for three users without multivariate testing access
Standard plan: $20-$700 per month depending on number of contacts for five users without multivariate testing access
Premium plan: $350-$1500 depending on number of contacts per month for unlimited users with multivariate testing access
Email subject line testing tools
An excellent subject line attracts a click, a weak subject line could get ignored, and an email recipient could trash a spammy subject line immediately. So as the first thing your subscribers see, it’s vital to evaluate your email subject line before hitting send. These tools help.
This is one of the best tools for assessing the quality of your email subject lines. Having this tool in your email arsenal allows you to gain insights on what can increase your open rate.
With CoSchedule email subject line tester, you’ll see the previews of your subject line on desktop and mobile, words that can increase and decrease opens, and a subject line score. The best part? This email subject line analyzer is a free tool.
Email Subject Line Grader is another free tool for evaluating subject lines. Like CoSchedule, this tool assigns a subject line score after assessing the word and character count, including word mixture and balance of your subject line.
Send Check It is a free email automation testing tool that ensures your subject line hits the mark.
After assessing your subject line, Send Check It provides recommendations on what to fix. These include technical problems with your subject line, scannability, length, readability, subject line sentiment, identifying spam words, and more.
Send smarter with Nutshell
After warming your email, testing your subject line, running A/B tests, and whatnot, you’ll need a centralized location to send, track, and measure the results of your campaign.
Nutshell CRM software integrates your marketing and sales data in one unified platform. This prevents you from juggling multiple software dashboards by providing the reports and communication tools you need in a single view.
Additionally, Nutshell’s email marketing platform lets you send newsletters, broadcasts, and personalized emails. It simplifies building and automating impactful marketing emails and enables you to create campaigns that engage your contacts and track interactions directly in your CRM.
Furthermore, you can use our A/B testing feature to optimize your campaigns for maximum audience impact and rely on detailed reports to evaluate and enhance your campaign effectiveness over time.
Plus, Nutshell integrates with 45+ business apps, has email preview functionality through email marketing, allows you to test different versions of your email, and we don’t deliver bounced emails, meaning your deliverability remains intact and you maintain optimum email ROI.
