email testing tools

15 Best Email Testing Tools For Optimized Delivery In 2024

In the world of online marketing, sending out perfect emails is super important. But making sure they’re just right can be tricky. That’s where email testing tools come in! These tools help you check everything from how your emails look to whether they’ll actually reach people’s inboxes. And guess what? There are lots of them out there, from ones that are totally free to ones made specifically for tech-savvy folks. So, let’s dive into the best email testing tools to make your email game strong!

Table of contents

Best email testing tools list

Here are the top 10 email testing tools out there, picked from a list of 15:


  1. Reflect: Great for testing workflows that involve both websites and emails.
  2. Stripo: Excellent for making and testing email templates.
  3. SendinBlue: Perfect for small to medium-sized businesses.
  4. Email On Acid: Ideal for checking email accessibility.
  5. MailChimp Transactional Email: Best for handling marketing automations.
  6. GlockApps: Top choice for testing if your emails might be marked as spam.
  7. MailCatcher: The best free tool for testing emails.
  8. Litmus ESP: Known for its smooth integrations with other platforms.
  9. MailTester: Super easy to use for testing emails.
  10. MailSlurp: Great for thorough testing of your entire email system.


Navigating through the multitude of email testing tools can be overwhelming. You’re looking to enhance your email campaigns for better reach and engagement, but with so many options, it’s hard to decide which tool suits your Digital marketing needs best.


Don’t worry, I’ve got you covered! Drawing from my experience with various email testing software, I’ve simplified things for you by compiling a shortlist of the top tools you should consider.

What Are Email Testing Tools?

Email testing tools are software designed to assess and refine email campaigns before they’re sent out. These tools analyze different aspects of emails such as layout, content, links, and compatibility across various email clients and devices. They help identify potential issues that could affect deliverability and ensure that emails appear correctly in recipients’ inboxes.

The Advantages and Uses of Email Testing Tools

Email testing tools offer several benefits. They enhance email deliverability by pinpointing and resolving issues that might trigger spam filters. These tools also ensure that emails display properly on different platforms, improving the recipient’s experience.


Additionally, they assist in optimizing email content for better engagement, such as crafting effective subject lines and ensuring functional links. By leveraging email testing tools, marketers and communicators can elevate their email communication, leading to more successful campaign outcomes.

Overviews Of The 10 Best Email Testing Tools

Below is a concise overview of each email testing platform highlighting their optimal use cases, notable features, and included screenshots for a quick look at the interface.


email testing tools

Reflect is a top choice for testing workflows that involve both websites and emails. It ensures your email communications are error-free and reach their intended recipients successfully. With a 14-day free trial and 30 minutes of free tests, Reflect offers a starting point for users. Pricing starts from $200 per month.


This AI-powered platform simplifies the creation of comprehensive end-to-end tests without manual code writing. It also supports cross-browser testing across popular browsers like Chrome, Firefox, Edge, and Safari, with regular infrastructure updates. Reflect’s advanced visual testing capabilities help uncover bugs that might be missed otherwise. It allows you to detect and resolve UI bugs before they affect email functionality.


Reflect features a built-in scheduler for easy test setup and execution. It seamlessly integrates with various CI/CD platforms, including Jenkins and CircleCI. Reflect offers customized pricing upon request and provides a free demo for new users. You can try it for free with 30 minutes of test coverage, unlimited test creation, and support for up to 5 users.


email testing tools

Stripo is perfect for those who want to create and test email templates effortlessly. With a free version available and plans starting from $12.50 per month, it’s accessible to all.


This platform simplifies email design with its drag-and-drop editor, requiring little to no HTML skills. It offers a variety of basic blocks to create dynamic content in real-time. Stripo was among the first to implement AMP for Email technology, enhancing interactivity.


Users can save and reuse email modules across different campaigns, and it supports customization with custom HTML code for interactive elements. With over 1000 responsive and mobile-optimized templates, Stripo provides ample choices.


Moreover, Stripo offers over 100,000 stock images and enables personalized email export and conversion tracking. It seamlessly integrates with over 60 ESPs/CRMs, facilitating easy email automation.


Stripo offers a lifetime free version, with other plans billed annually: Basic ($150 or $12.50 per month), Medium ($450 or $37.50 per month), Pro ($950 or $79 per month), and Prime (pricing available upon request).


email testing tools

SendinBlue stands out as the ideal choice for small to medium-sized enterprises (SMEs). With a free plan available and starting at $25 per month, it’s budget-friendly.


This platform offers a comprehensive marketing hub tailored to SMEs, featuring automation tools, email validation, reporting, and templates for email design. SendinBlue’s email automation tool enables users to create rules and execute commands based on user actions, facilitating targeted communication.


With SendinBlue, users can leverage behavioral, email, and contact data to create basic and advanced workflows, segment contacts, and manage email lists based on website activity. Its all-in-one approach to email creation, marketing, automation, and testing simplifies the process for SMEs.


SendinBlue’s pricing starts at $25 per month for up to 20,000 emails, with a free version available with some limitations. It’s a cost-effective solution for SMEs looking to streamline their email marketing efforts.

Email On Acid

Email On Acid specializes in testing email accessibility, making it the go-to choice for ensuring that your emails are easy to access and navigate for all users. With plans starting from $74 per month, it’s a valuable investment for maintaining brand reputation and enhancing marketing ROI.


This platform focuses on quality assurance and pre-deployment functionality, ensuring that emails are error-free and visually consistent across various devices and platforms. It streamlines the testing process with features like campaign prechecks, URL validation, and image optimization.


Email On Acid offers checklists for important aspects such as UTM validation and ADA compliance, improving email deliverability rates by conducting spam checks and providing access to blacklisted domains. It enables users to verify email lists against over 20 popular spam filters and test IP addresses against block list services.


The platform includes an editor for building templates and collaboration tools for team efficiency. Email On Acid offers four pricing tiers with a free trial period and annual billing: Basics ($74/month), Premium ($134/month), Professional ($449/month), and Enterprise (custom-priced).


email testing tools

MailChimp Transactional Email is the top choice for those looking to streamline marketing automations. It’s an add-on for existing Mailchimp users, allowing them to send emails through their Transactional API or SMTP integration.


As an all-in-one marketing platform, Mailchimp offers a range of features including content creation tools, marketing analytics, and advanced email testing options. It’s AI-powered and designed with an intuitive user interface, making it accessible even to users with limited technical knowledge. Mailchimp provides detailed reporting on deliverability, open rates, click-throughs, and conversions.


With Mailchimp, you can automate tasks and communications, managing transactional deliveries efficiently. The platform is scalable, enabling you to send a large volume of emails at once. Additionally, Mailchimp offers website hosting and design services, allowing users to create landing pages effortlessly using basic templates or custom code.


To access the Transactional Email add-on, you’ll need a Standard Mailchimp plan or higher, starting at $14.99 per month. Then, you can add $20 per block (equivalent to 25,000 emails), with lower rates available for bulk purchases.


email testing tools

GlockApps is the go-to solution for testing email campaigns to ensure they don’t end up in spam folders. With a basic plan starting at $59 per month, GlockApps offers a comprehensive suite of tools to address email deliverability issues before sending.


This tool provides various features, including a “Reputation Check” to audit your IP address and domain against industry blacklists, and DMARC Email Analytics for monitoring and managing email impersonation attempts. GlockApps generates detailed reports on spam and blacklist issues, enabling users to troubleshoot and improve email deliverability.


These reports are invaluable for testing marketing campaigns and the performance of email marketing providers. They display all IP addresses used to send emails and highlight any blacklisting, giving users a clear overview of their campaign’s effectiveness.


GlockApps also offers a free version for personal use, making it accessible to individuals as well as businesses.


email testing tools

MailCatcher is hailed as the best free email testing tool available. It’s completely free to use, making it accessible to everyone.


This tool is designed to intercept emails from any web or mobile application and store them for display. MailCatcher operates a fake SMTP server and showcases HTML and CSS emails, as well as plain text emails and source versions when applicable. It even rewrites HTML to enable the display of embedded images and can open links in a new window, ensuring thorough testing of email formatting before sending to clients.


MailCatcher offers instant mail display if WebSockets are supported in your browser, updating every thirty seconds otherwise. It provides command-line options to override default SMTP/HTTP IP and port settings, allowing users to customize their testing experience according to their needs.

Litmus ESP

email testing tools

Litmus ESP is the top choice for seamless integrations with various email service providers (ESPs). With a 7-day free trial and starting at $79 per month for the basic package, Litmus ESP offers a comprehensive suite of features for building, testing, and analyzing emails across all ESPs.


This tool allows users to pinpoint specific reasons for email delivery failures and assess image loading times, providing insights into real-world inbox processing. Litmus’s user-friendly interface offers quick-loading screenshots of current email clients, organized email folders, and preview testing capabilities. It also includes a Builder for testing code against different email clients, streamlining processes. Additionally, Litmus facilitates team collaboration through commenting and editing functionalities.


Litmus seamlessly connects with a wide range of ESPs and other services, including Acoustic Campaign, Adobe Campaign Standard, Adobe Marketo, Hubspot, Oracle Eloqua, Oracle Responsys, Pardot, Salesforce Marketing Cloud, and SAP Marketing Cloud.


With its robust features and integrations, Litmus ESP is a valuable tool for marketers seeking to optimize their email campaigns.


MailTester is recognized as the best choice for straightforward email testing. It’s user-friendly and offers a free trial, with pricing starting at $19 per month for one user.


This cloud-based email verification tool assists businesses in verifying email domains and syntax. It serves as an essential first step in email testing, featuring an intuitive interface suitable for users with varying technical expertise.


MailTester provides a range of tools, including Spam Trap Removal to identify spam trap emails in your lists, and Syntax Verifier to detect and remove emails with invalid syntax. It supports both manual and automatic email verification using API, and allows users to download segmented results for further analysis.


With its simplicity and effectiveness, MailTester is a valuable asset for businesses looking to ensure the accuracy and deliverability of their email campaigns.


email testing tools

MailSlurp stands out as the top choice for comprehensive end-to-end email testing. With a 7-day free trial and starting at $21.66 per month (billed annually), MailSlurp offers a suite of features tailored for thorough email testing.


This “email as a service” tool provides email sandbox APIs, deliverability dashboards, auto-forwarding, webhooks, and inbox routing, trusted by companies like Trivago, Ring, and Panasonic.


Using its REST API, MailSlurp enables programmatically testing transactional emails and user engagement by sending real emails to real addresses from your application. It’s favored by developers and QA testers for its ability to create real inboxes on demand, send and receive emails and attachments through code, and test with various frameworks and languages like Selenium and Jest.


MailSlurp utilizes a custom SMTP MailServer and AWS SES for sending and receiving emails at scale. It allows you to send email design templates to contact groups, track email opens with actual addresses, and test user authentication, forgotten passwords, and email verification.


With its robust features and versatility, MailSlurp is an essential tool for ensuring the functionality and reliability of email campaigns.

Addition options for email testing

Here are a few additional options that didn’t quite make it to the top list:


11. Wormly: Ideal for monitoring both email and web performance, ensuring optimal uptime and functionality.

12. MailHog: Perfect for app developers, providing a platform to capture, inspect, and test email messages sent from development environments.

12. MailTrap: Specifically designed for email testing in staging environments, allowing users to simulate email sending without affecting live systems.

13. ZeroBounce: An email validation service that utilizes AI-powered deliverability scoring to improve deliverability and open rates, ensuring email lists are clean and effective.

14. SparkPost: A tool focused on email sender reputation, leveraging data-driven analytics to analyze bounce, delivery, and engagement events and optimize email deliverability.

15. SparkPost: A tool focused on email sender reputation, leveraging data-driven analytics to analyze bounce, delivery, and engagement events and optimize email deliverability.

Selection Criteria for the Best Email Testing Tools

When selecting the best email testing solutions, consider the following criteria:


  • User Interface (UI): Look for a user-friendly dashboard with clear, concise, and organized features. A pleasant user experience enhances usability.
  • Usability: Choose platforms that are effective yet easy to use, with extensive documentation for reference and training purposes. Accessibility and ease of navigation are crucial.
  • Integrations: Seek email testing tools with seamless integration opportunities, including popular email providers like Gmail, Outlook, AOL, iCloud, and social media platforms. Ensure integration with analytics tools for efficient data analysis.
  • Value for Money: Assess the features and access levels offered in relation to the cost. Determine whether the tool provides sufficient value for the investment.

Key features in Email Testing

Key Features to Consider:


  • Email Integration: Ensure compatibility with major email providers to streamline testing across different platforms.


  • Spam Tests: Verify whether the tool can detect potential spam triggers, ensuring your emails have a higher chance of reaching recipients’ inboxes.


  • Sender Score: Evaluate the software’s ability to assess your sender reputation, indicating how likely your emails are to reach the intended audience.


  • Defect Tracking: Look for features that flag and log any issues encountered during testing, facilitating timely resolution by your team.


  • Deliverability Optimization: Choose a platform that provides insights to improve email deliverability, increasing the likelihood of emails reaching their destination.


By considering these criteria and key features, you can select an email testing solution that meets your needs effectively and efficiently.

What are Common challenges in email testing?

Common challenges in email testing include:


  • Render Variability: Emails may appear differently across various email clients, such as Outlook, Gmail, and Apple Mail, due to differences in HTML/CSS rendering.


  • Responsive Designs: Ensuring that email designs display properly on different devices, including mobile phones, tablets, and desktops, can be challenging.


  • Spam Filters: Crafting email content and designs to avoid triggering spam filters is crucial for ensuring emails reach recipients’ inboxes instead of being flagged as spam.


  • Attachments & Links: Links and attachments can trigger spam filters or fail to work as intended, requiring extra care when including them in emails.


  • Email Size: Large emails can lead to slow loading times or display issues, highlighting the importance of optimizing email size while maintaining quality.


  • Plain Text vs. HTML: Ensuring that both plain text and HTML versions of emails exist and are synchronized is essential for accessibility and deliverability.

How do email testing tools improve deliverability?

Email testing tools help improve deliverability by addressing these challenges:


  • Spam Filters: Tools emulate various spam filters and provide actionable tips to reduce spam scores, increasing the likelihood of emails reaching recipients’ inboxes.


  • Email Previews: Tools allow users to preview how email designs appear across multiple email clients, operating systems, and devices, helping to avoid visual glitches.


  • Link Validators: Many tools check for broken links, ensuring a smooth user experience.


  • Load Time Analyzer: Tools analyze email size and loading speed, enabling users to optimize email content for faster loading times.


  • Authentication Checks: Tools validate SPF, DKIM, and DMARC authentication, ensuring email legitimacy and improving deliverability.


  • A/B Testing: Many tools support A/B testing of email subject lines and segmentation of email delivery times, helping to optimize email performance and engagement.


Overall, email testing tools help improve deliverability, open rates, and conversions by addressing common challenges and optimizing email campaigns for success.

How to measure ROI using Email Testing Tool?

Measuring the ROI of using an email testing tool involves:


  • Tracking deliverability rate increase: Measure email deliverability before and after tool implementation to assess improvements.
  • Monitoring email engagement metrics: Observe changes in open rates, click-through rates, and conversion rates to gauge tool effectiveness.
  • Reducing bounce rates: A decline in email bounce rates indicates better list health and targeting, leading to cost savings and increased opportunities.
  • Calculating time saved: Compare manual testing hours pre- and post-tool implementation to quantify efficiency gains.
  • Estimating error costs avoided: Track errors caught by the tool to estimate potential brand damage or lost sales and quantify the value of error prevention.
  • Analyzing A/B testing results: Calculate the monetary difference between A/B test versions to assess the tool’s impact on conversion rates.


Deduct the tool’s cost from the gained value to determine the net ROI of using the email testing tool.


In conclusion, investing in an email testing tool can yield significant returns for your email marketing efforts. By addressing common challenges such as render variability, responsive designs, spam filters, attachments and links, email size, and plain text vs. HTML formatting, these tools help improve deliverability, engagement, and overall campaign effectiveness.


When measuring the ROI of using an email testing tool, consider factors such as deliverability rate increase, email engagement metrics, bounce rate reduction, time saved, error costs avoided, and A/B testing results. By analyzing these metrics before and after tool implementation, you can demonstrate the tangible benefits and justify the investment to stakeholders.

Frequently Asked Questions

Email testing involves evaluating and optimizing email campaigns before sending them to recipients. It includes checking elements such as layout, design, content, links, and compatibility with different email clients and devices.

Email testing is important because it helps ensure that emails are delivered successfully, appear as intended in recipients’ inboxes, and engage users effectively. It helps identify and fix issues that could affect deliverability, user experience, and campaign performance.

Common challenges in email testing include render variability across different email clients, responsive design compatibility, spam filter avoidance, attachment and link functionality, email size optimization, and maintaining consistency between plain text and HTML versions.

Email testing tools improve campaign performance by providing features such as spam filter testing, email previews across multiple devices, link validation, load time analysis, authentication checks, and A/B testing capabilities. These tools help identify and address potential issues before sending emails, resulting in improved deliverability, engagement, and conversion rates.

You can measure the ROI of using an email testing tool by tracking metrics such as deliverability rate increase, email engagement metrics, bounce rate reduction, time saved, error costs avoided, and A/B testing results. By comparing these metrics before and after tool implementation and subtracting the tool’s cost, you can determine the overall return on investment.