21 Exceptional Email Testing Tools to Optimize Your Campaigns

Hamna Abid
Hamna Abid

Last updated on

June 15, 2024

Don't overlook the power of email testing tools! You've put in the time to perfect your copy and design, but without testing, you risk errors like email display issues, spam folder mishaps, and formatting blunders. 

Email testing tools have become an indispensable requirement for today's marketers rather than just an optional addition. Creating persuasive email campaigns that successfully pass spam filters is an elusive goal.

However, achieving this goal necessitates the thorough testing of your messages. By diligently assessing and optimizing your email content, you can guarantee an exceptional experience for your subscribers and enhance the effectiveness of your business communication. In this article, we’ll discuss some of the best email testing tools. So, let’s get into it!

Email Preview And Spam Testing Tools

Emails can look quite different across various email clients, with over 3000 potential readings for a single email. This diversity extends to email views on desktop and mobile devices as well. Thankfully, email preview tools resolve by addressing these variations effectively.

But that's not all! These handy tools also offer the advantage of spam testing, ensuring that your carefully crafted emails reach your recipients' inboxes rather than getting lost in spam folders. 

Here are some best email preview and spam testing tools that deserve your attention:

1. MailTrap

MailTrap is a versatile platform that offers many email tests, including preview testing. It allows you to verify the functionality of your HTML across different email clients and ensure a seamless experience for your recipients.

One of the standout features of MailTrap is its using a simulated server environment for all testing purposes. This ensures that your test emails are correctly sent to your subscribers. With MailTrap, you can rest assured that your tests are conducted in a secure staging environment.


  • Spam Testing
  • Mailtrap API Access
  • Detailed Email Headers
  • Safe Testing with Fake SMTP Server
  • Priority Support


  • Mailtrap offers a free plan as well as five pricing options.
  • The pricing options range from $14 to $399 per month.

2. Litmus

Litmus is one of the best email testing tools trusted by organizations across all scales, from small businesses to large enterprises.

You can visualize your email's appearance on all the best email services, including Outlook, Apple Mail, Gmail App, Samsung Mail, etc.

Its advanced Spam Testing feature allows you to evaluate your emails for compliance with spam filters and promptly receive notifications regarding blocklisting or potential DMARC records. With Litmus, you can optimize your email campaigns and ensure exceptional experiences.


  • Pre-send Spam Testing
  • Seamless Integration with 20+ Apps
  • Extensive Support
  • Email Previews of 100+ Email Clients 
  • Automated Quality Assurance


  • Seven-day free trial.
  • Basic Plan: $99 monthly, offering 1,000 email previews for one full user.
  • Plus Plan: $199 monthly, offering 2,000 email previews for up to five full users.
  • Enterprise Plan: Custom pricing is available for enterprise-level needs.

3. Email on Acid

Email on Acid has established a strong reputation in email testing circles thanks to its expanding range of features. With the ability to preview test emails on 70 different clients and devices, Email on Acid ensures optimal email appearance across various configurations. Collaboration is a key focus for Email on Acid, which makes it an excellent choice for small businesses or groups working on newsletters as a team. 


  • Unlimited Email Previews
  • Spam and Deliverability Checks
  • Full Content Checking of links, Images, and Spelling 
  • Collaborative Commenting
  • Email and Chat Support


  • Seven-day free trial
  • The Basics plan: $99/month (1 user). 
  • Premium plan: $179/month (3 users). 
  • Professional plan: $599/month (10 users). 
  • Enterprise plan: Custom pricing available.

4. Moosend

Moosend is an ultimate email marketing service that empowers you to craft, automate, test, and send captivating email campaigns.

Besides email creation, lead generation, and email list management features, Moosend goes the extra mile by providing advanced design and delivery testing capabilities.

This ensures your messages maintain their impeccable appearance and reach the inbox flawlessly. This feature is particularly valuable for marketers who leverage the HTML builder.


  • Drag-n-drop Email Builder
  • Preview Email Functionality
  • Marketing Automation Workflow Editor
  • Content Spam Checker Option
  • Email Analytics and Metrics
  • A/B Testing Tool
  • Landing Pages and Online Forms


  • Mailtrap offers paid plans starting from $9/month.
  • Plans include unlimited email marketing, forms, landing pages, and email testing.
  • Free account is available to try out the tools.

5. Unspam

Unspam email is an innovative online tool designed to help you optimize your email marketing efforts by preventing your messages from ending up in spam folders. This service analyzes key aspects of your emails and provides a spam score and inbox placement, alongside a predictive heat map to visualize engagement with your email content.


  • Sender Policy Framework (SPF)
  • Domain Keys Identified Mail (DKIM)
  • Domain-based Message Authentication, Reporting & Conformance (DMARC)
  • Reverse DNS checks
  • Detection of broken links and short URLs
  • Domain suffix and age verification
  • List unsubscribe headers
  • HTML body best practices


  • Unspam offers a free plan as well as three pricing options.
  • The pricing options range from $9 to $29 per month.

Email Testing Tools For Verifying Invalid Addresses

Sending emails to invalid addresses leads to unopened bounces that can impact your reputation and make future emails look like spam.

However, you can overcome this challenge by using email verification tools to ensure a clean and reliable email list.

By permanently cleaning your list with these tools, you can proactively prevent spam-like appearances and maintain a positive sender reputation.

Let’s have a look at the best email testing tools for verifying invalid addresses.

1. Mailmunch

Mailmunch's Email Testing Tool is a comprehensive solution designed to empower marketers with advanced features for email campaign optimization.

This powerful tool lets you preview your emails across multiple email clients, devices, and browsers, ensuring a consistent and visually appealing experience for every recipient. 

It verifies links and images, ensuring all elements within your emails function correctly. With detailed insights and analytics, you can get valuable data to optimize your campaigns further. 


  • Email preview on multiple devices and email clients
  • Real-time rendering of email content
  • Spam filter testing
  • Image and link verification 
  • HTML and CSS validation 
  • Text version rendering 
  • Inbox placement testing
  • Subject line and preheader display 
  • Collaboration tools 
  • Detailed reporting and analytics


  • Mailmunch's Premium plan is priced at $13.99/month.
  • It includes unlimited forms, landing pages, and campaigns.
  • Features include email automation, abandoned cart emails (for Shopify), premium templates, and advanced analytics.

2. Zerobounce

ZeroBounce is a leading email verification tool that accurately validates your email list. Whether dealing with a small or large subscriber base, ZeroBounce efficiently removes invalid email addresses.

ZeroBounce provides intuitive email validation APIs that enable automated assessment of contact quality during data capture. With built-in email deliverability tests and real-time blacklist monitoring, you can optimize your email campaigns for maximum reach and effectiveness. 


  • Seamless integration with 40+ apps
  • Accurate and free unknown result verification
  • 24/7 customer support
  • Precise IP address
  • Comprehensive blacklist monitoring
  • Advanced validation tools
  • The flexibility of multiple API keys
  • Reliable email server test 


  • Monthly Option: For $15 per month, you can validate up to 2,000 emails.
  • Pay-as-you-go Option: Alternatively, you can choose the pay-as-you-go option, which costs $16 to validate 2,000 emails.

3. NeverBounce

NeverBounce stands out as a reliable email verification tool, offering a range of features akin to Clearout.

With real-time email verification, NeverBounce efficiently verifies lists of any size. The highlight? Seamlessly automate list cleaning by integrating your email provider with NeverBounce, ensuring utmost accuracy and optimal email deliverability for your campaigns.


  • API access for seamless integration
  • Custom list tagging
  • Bulk list email cleaning 
  • Automated list cleaning 
  • Integration with 80+ apps
  • Real-time email validation


  • Monthly Plan: For validating 5,000 emails, you can opt for the monthly plan priced at $49.
  • Pay-as-you-go Option: You can choose the pay-as-you-go option, which costs $40 for validating 5,000 emails.
  • Free Trial: Before committing, you can take advantage of their free trial to test the service and evaluate its suitability for your needs.

4. DeBounce

DeBounce is a comprehensive email validation tool that offers a range of powerful features to ensure the accuracy and deliverability of email addresses. Its main features include bulk email validation, allowing users to verify large lists of email addresses efficiently. The Email Validation API enables seamless integration of DeBounce's validation services into existing applications or platforms. The lead finder feature helps users generate potential email addresses based on first name, last name, and domain name, while the data enrichment feature enhances email data with additional information. These features make DeBounce a valuable tool for businesses and individuals looking to maintain a clean and reliable email database.


  • Email address validation
  • Duplicate email removal
  • Spam-trap email detection
  • Catch-all domain identification
  • Free trial
  • Bulk email verification
  • Customizable validation output


DeBounce offers a flexible pay-as-you-go option, allowing you to purchase credits as needed. Pricing ranges from $10 for 5,000 credits to $1,500 for 5 million credits, with a minimum price of 0.0003 USD per validation.

5. Clearout

Clearout is an advanced email verification tool that shares similar features with ZeroBounce. It validates email addresses at the capture point, ensuring only valid emails enter your list. 

Whether you collect emails through your website, pop-ups, checkouts, surveys, chatbots, or newsletters, Clearout verifies them beforehand.

Clearout eliminates duplicate emails, incorporates spam detection algorithms, and verifies whether recipients' mailboxes accept new messages. These comprehensive features ensure your email list is clean, optimized, and can reach the intended recipients.


  • Foolproof gibberish check
  • Seamlessly integrates with over 100 popular apps
  • Effortlessly removes duplicate email entries
  • Robust greylisting verification 
  • Proactively monitors blacklists 
  • Advanced spam trap detection 
  • Easy-to-use API for seamless integration and automation


  • Monthly Pricing: For validating 5,000 emails, you can select the monthly pricing option at $31.50.
  • Pay-as-you-go Option: You can choose the pay-as-you-go option, which costs $35 for validating 5,000 emails.
  • Free Monthly Validations: Clearout also provides 100 free validations at no extra cost.

Email Testing Tools for Email Deliverability 

When it comes to email marketing, ensuring high deliverability is crucial for the success of your campaigns. That's where email testing tools for email deliverability come in.

These tools provide valuable insights and functionalities to help you optimize your emails and increase the chances of reaching your recipients' inboxes. 

1. SendForensics

SendForensics is an email deliverability suite that leverages AI insights to assess the likelihood of your emails reaching your recipients' inboxes. With its comprehensive capabilities, SendForensics evaluates your emails against global filtering systems, ISPs, and even human recipients, providing valuable insights into your email's quality.

Stay in control of your deliverability by monitoring key elements like sending infrastructure, email content, IPs, and domains.

This empowers you to optimize your email strategy and proactively address potential deliverability issues. 


  • 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 reputation analysis
  • AI-driven insights for email content and sending infrastructure


  • 14-day free trial
  • Brand plan: $49/month for 2 users
  • Company plan: $79/month for 5 users
  • Agency plan: $199/month for 10 users

2. GlockApps

GlockApps is a powerful email deliverability solution offering a range of features to optimize your email performance.

GlockApps gives you valuable insights into inbox placement, DMARC analytics, bounce tracking, and IP reputation monitoring.

The platform also provides free spam testing. By monitoring your IP, website, and authentication records, GlockApps helps maintain email health and improve conversions.


  • Advanced bounce analytics
  • Comprehensive email spam tests
  • DMARC messages validation
  • Dynamic email template editor 
  • Real-time IP reputation monitoring


  • Access to a free account
  • Basic plan: $59/month for one user
  • Business plan: $99/month for five users
  • Custom plan creation option

3. Email Round-Trip Monitoring

Email round-trip monitoring involves sending a specialized "test" email to track its journey from your email to the recipient's, using a unique email, and receiving a report detailing whether the email was successfully delivered. The service helps you ensure your regular emails reach their intended destinations smoothly.

Key features:

  • Supporting multiple protocols and authentication methods
  • Available primary and secondary manual server configurations
  • Multiple mail submit and delivery scenarios
  • Monitoring interval up to every 10 minutes
  • Multiple monitoring locations


  • 1-hour interval, 1 monitoring location — $7.00/month
  • 30 min. interval, 1 monitoring location — $11.00/month
  • 15 min interval, 1 monitoring location — $21.00/month Customization available

Email Warm-Up Tools For Improved Deliverability

If you find yourself with a fresh email address or one that hasn't been active for some time, it's essential to give it a warm-up.

Email warming is a strategic process that builds a positive reputation for your IP, ensuring your emails avoid the dreaded spam folder.

While manually warming emails is an option, fantastic tools stream the process. Here are a few email warm-up tools:

1. Lemwarm By Lemlist

Lemwarm stands out as a top-tier email warm-up tool, ensuring your emails steer clear of spam folders.

This innovative tool takes a gradual approach, sending and interacting with personalized emails based on your email domain's age.

What sets Lemwarm apart is its unique method of exchanging emails with a vast network of over 20,000 individuals from more than 100 countries, eliminating the need for fake accounts. 

The outcome? A stellar sender reputation and optimal email delivery to your recipients' primary inboxes.


  • Genuine human engagement
  • Domain flexibility
  • 25+ years domain age range
  • Enhanced email deliverability


  • Monthly billing: $29 per month
  • Yearly billing: $25 per month

2. MailReach

MailReach is an intelligent email warm-up tool designed to optimize your email deliverability. Its incremental sending and engagement strategies ensure that your emails land in the primary inbox rather than the spam or promotion folders.

What sets MailReach apart is its unique feature of exchanging emails with multiple email service providers, including Gmail, Outlook, and more. This helps maintain a high sender reputation across different platforms.


  • Access to 12,000+ real inboxes
  • Email reputation monitoring
  • Intuitive monitoring dashboard
  • Real-time blacklist and DNS monitoring
  • Multi-service provider email warm-up


  • Starter Plan: $25/month per email account (1-5 accounts).
  • Scale Plan: Starts at $19.50/month per email account (6+ accounts).

3. Folderly

Folderly, an AI-based email warmer, identifies and resolves email deliverability issues. With Folderly, you can effortlessly set up, track, and monitor the progress of your email warm-up process.

Folderly offers a range of other email marketing solutions, including email deliverability audits, email placement testing, and an SPF Generator.


  • Smart sender generation for personalized interactions
  • Cutting-edge AI-powered interactions with GPT-3 technology
  • Comprehensive email warm-up dashboard for efficient monitoring
  • Seamless integration with a wide range of 10 popular apps
  • Accurate email placement test 


  • Folderly offers a straightforward pricing structure for its email warm-up feature, priced at $49 monthly. 

4. Autowarmer By Quickmail

AutoWarmer stands out as a robust email warming tool, offering a range of features similar to its counterparts.It offers a free-forever plan, making it an attractive option for budget-conscious users.

However, it's important to note that the free plan is limited to warming Gmail, Outlook, and SMTP inboxes. For advanced features like the warm-up deliverability report, upgrading to a paid plan is necessary. 


  • Advanced email engagement tracking
  • Intelligent automated stop-on-reply feature 
  • Seamless automated follow-ups 
  • Robust bounce detection
  • Real-time live notifications
  • Powerful A/B testing 


  • Free Plan: Warm up inboxes on Gmail/Outlook/SMTP at no cost.
  • Basic Plan: $49 monthly.
  • Pro Plan: $97 monthly.

A/B Testing tools

A/B testing is a powerful method for evaluating the impact of different email elements on your campaign performance.

By testing variations of your subject line, body copy, personalization, and CTA, you can optimize your emails for better results.

With the right A/B testing tools, you can determine the most effective elements that drive higher open rates and conversions.

1. VWO

VWO is a widely recognized A/B testing tool trusted by global brands for testing various aspects of their campaigns, including emails, web pages, apps, and products.

With VWO, you can easily test different elements of your email campaigns and determine the best-performing variant based on real-time performance metrics.

While VWO offers multivariate testing capabilities to evaluate multiple elements simultaneously, this approach allows for more focused analysis and optimization of your email campaigns.


  • Visual editor with support for HTML attributes and CSS modifications
  • API access (available for enterprise users)
  • Seamless integration with over 40 apps and platforms
  • Advanced report segmentation for in-depth analysis
  • Multivariate testing capability to evaluate multiple elements simultaneously
  • Email split testing for comparing different versions of emails and measuring their performance


  • Starter: Free plan available
  • Growth Plan: $286/month. 
  • Pro Plan: $657/month.
  • Enterprise Plan: $1,151/month.

2. Optimizely

Optimizely is a robust A/B testing tool that empowers you to experiment with different elements in your email campaigns. With its multivariate analysis capabilities, you can test multiple variables simultaneously to uncover valuable insights.

Moreover, Optimizely provides a wide range of digital experience tools, including e-commerce, website optimization, content management, and marketing planning, offering a comprehensive solution for enhancing your overall online performance.


  • API access
  • Win rate reporting
  • Email split testing
  • 180+ app integrations
  • Collaborative  platform
  • Extensive support 


  • Optimizely's pricing for the Grow, Accelerate, and Scale plans is not publicly available.
  • Contact Optimizely's sales team for detailed pricing information and to discuss your specific needs.
  • They will provide personalized pricing details and assist you in selecting the right plan.

3. Mailchimp A/B Testing Software

Mailchimp, a renowned email marketing platform, provides powerful A/B testing features. Within Mailchimp, you can effortlessly target a specific segment from your email list for your campaign and select the element you wish to test. You have the flexibility to define the percentage of recipients for the test and establish the criteria to determine the winning variant. 


  • Precision testing with A/B experiments
  • Advanced optimization with Multivariate testing
  • Laser-targeted segmentation
  • Seamless integration with 200+ apps
  • Comprehensive support channels


  • Free plan: No email testing access.
  • Essentials plan: $13/month.
  • Standard plan: $20/month.
  • Premium plan: $350/month.

Email Subject Line Testing Tools

Crafting a compelling subject line is crucial as it greatly impacts email open rates. To ensure the effectiveness of your subject lines, evaluating them before sending out your emails is essential. Here are some helpful tools for subject line evaluation:

1. CoSchedule Email Subject Line Analyzer

CoSchedule's email subject line tester is a top-notch tool for evaluating the quality of your subject lines.

Utilizing this tool gives you valuable insights into optimizing your open rates. With features such as desktop and mobile previews, identification of impactful and detrimental words, and a subject line score, this free analyzer is a must-have in your email toolkit.


  • Desktop and mobile previews
  • Impactful and detrimental words
  • Subject line score
  • Free tool


  • Unlimited publishing. $29/month.

2. Email Subject Line Grader

Email Subject Line Grader is a valuable tool that helps you evaluate the quality of your subject lines. Like CoSchedule, this tool analyzes various factors such as word and character count, word mixture, and balance to give you a subject line score. With its user-friendly interface and free availability, Email Subject Line Grader is an excellent resource for optimizing your email subject lines.


  • Assigns a subject line score based on various factors
  • Analyzes word and character count
  • Evaluates word mixture and balance
  • Provides insights to optimize subject lines
  • User-friendly interface
  • Free to use


  • Email Subject Line Grader is a free tool for evaluating subject lines. 

3. Send Check It

With Send Check It, you'll receive a comprehensive assessment of your subject line, with actionable recommendations to improve its effectiveness.

This tool covers everything from identifying technical issues and optimizing scannability to refining length, readability, and sentiment. It even helps you avoid spam words that can hinder your email's performance.


  • Free email testing tool for subject lines
  • Assesses subject lines for technical problems, scannability, length, readability, and sentiment
  • Provides recommendations on how to improve subject lines
  • Helps identify spam words and optimize subject line content
  • User-friendly interface
  • Enables you to ensure your subject line is effective before sending emails


  • $69 user/month
  • 29 Per email Per month when paid yearly
  • $0.99 per user/month


After all the efforts you put into warming your email, testing subject lines, and running A/B tests, it's crucial to have a centralized platform to send, track, and measure your campaign results. This ensures efficient management and optimization of your email marketing efforts.

MailMunch is an exceptional tool that combines powerful features, ease of use, and comprehensive analytics to help you achieve your email marketing goals.

Whether you are a small business owner or a seasoned marketer, MailMunch can be a valuable asset in driving engagement, conversions, and business growth.

Author Bio

Hamna Abid

Say hello to Hamna, a tiny wordsmith who loves combining humor and creativity with masterful precision during the day, and a caped Batman that saves the world during the night. She ensures that every piece not only ranks high but also resonates with the audience.


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