Posted On: Sep 20, 2023
Posted By: John Duff
Best Email Testing Tools to Help You Drive Revenue

Recent figures about email marketing state that for every $1 spent on email, there is an ROI of about $36. Unfortunately, not every email marketing campaign can achieve a similar ROI due to the lack of proper email testing tools usage.

These email testing tools can turn around the scenario as they preview and analyse the email before sending it to the recipient. It is done to optimize the existing email campaign that will help you generate better revenue.

Let’s paint you a picture; for example, the marketing team sends out 15,000 emails to trail users, who might be willing to take up a yearly subscription costing $504. If the open rate is 30%, the potential customers are 4500 users. Regrettably, the marketing team didn’t optimize the display for Outlook users. Considering that 10% use Outlook, there will be an email rendering issue for 450 people. Considering that the conversion rate is 30%, the marketing team has to leave out 135 potential customers, as they will never click on the CTA. In terms of the money, the venter lost $68,040 (135 x $504), presumably as they didn’t miss out on testing the email.

The global email users are estimated to reach 4.6 billion in 2025, generating a better stage for businesses to capitalize on.

In this blog, we will take you through the best emailing testing tools that significantly diminish the email rendering and inbox placement challenges, generating more return on investment for your business.

Spam Testing and Email Preview Tools

Every email message reflects differently for different clients and devices like desktops, tabs, and mobile creating the possibility of 300,000 potental renderings for an email.

Let’s discuss the best email testing tools that can be used for email rendering and spam testing to ensuring email inbox placement

1. Litmus

  • Small to enterprise-level organizations use litmus, as it is one of the finest email testing tools. Litmus provides a platform to foretaste the email appearance on 100+ email clients like Apple Mail, Samsung Mail, Gmail App, and Outlook.
  • The spam feature takes the email through an evaluation process against multiple spam filters. Later, notify if the email is set up incorrectly, set up your DMARC record, or if the email is block-listed.


2. Mailtrap

  • Mailtrap list all the issues it finds in the HTML and CSS. With Mailtrap, you won’t get a preview of 100+ email clients, but it will notify you of all the red flags in the email with respect to its significant client—for example, Outlook and Gmail.
  • Apart from working on spam issues and previews, Mailtrap can conduct all the email testing on a fake server. Henceforth, the probability of sending a test email by mistake to an email subscriber is zero.


3. Email on Acid

  • Organizations like The New York Times, Toyota, and IBM use this email testing tool.
  • Marketers and developers consider it one of the finest email testing tools.
  • Email on Acid observes email appearance over 90+ email clients and devices.
  • Users can also get insights on the deliverability rate before pressing the send button, as their email messages will be tested against 23 spam filters.


4. Email Preview Service

  • To access the email appearance of over 54 clients, developers, marketers and designers use Email Preview Service. It has simple ways to test emails, like uploading the saved HTML code, forwarding the email to a special preview in my email inbox, submitting the email via API, and lastly you can copy and paste your email.
  • Fixing spam and identifying issues is an effortless work for this tool; it checks your original IP address against over 50 nearly all familiar industry blacklists.

Email Preview Services

Email Testing Tools for Deliverability

The delivery rate and deliverability rate are two different assertions. Deliverability refers to the ability of the email message to be delivered to the beneficiary’s email inbox. Email deliverability rate is the percentage of email accepted by internet service providers.

1. SendForensics

  • SendForensics is a state-of-the-art deliverability suite that uses numerous AI insights to evaluate an email’s capacity to reach a recipient’s inbox. The email quality assessment is done through three levels of testing; it is taken through a global filtering system, human recipients, and ISPs.
  • Adding SendForensics to your email toolbox permits you to keep track of sending infrastructure, email content, IPs, domains, email content and all the other things that can impact email deliverability. Additionally, SendForensics has an email preview functionality.

Send Forensics

2. GlockApps

  • When looking for inbox insights, bounce tracker, free spam testing and DMARC analytics in one place, you must use GlockApps as it makes provision for comprehensive email deliverability.
  • GlockApps can keep a check on email reputation, improve website conversion, and finally maintain email health. As uptime monitoring of your IP, SPF, DKIM, website, and DMARC all of it is possible with GlockApps. Additionally, it comes with a free spam checker.


Invalid Address Checking With Email Testing Tools

Email bouncing back without being opened is something many marketers have experienced when they send emails to invalid email addresses. The higher the bounce rate, the more the brand reputation gets a hit, making the future bulk emails look like spam. The tools listed below are here to reduce the bounce rates.

1. ZeroBounce

  • Want an immaculate list of 100, 1000 or 10,000 subscribers? ZeroBounce is a tool that takes seconds to a few minutes to produce a list of invalid email addresses.
  • This tool comes integrated with intuitive email validation APIs, which assess and automate the standard of your contacts while capturing them. Email deliverability and real-time blacklist are two additional features with zerobounce.


2. Clearout

  • Validating the subscriber’s email address at the point of capture is what Clearout is capable of. You might capture your emails via exit pop-ups, websites, woo-commerce checkout, surveys/polls, newsletters, and chatbots, with clearout on-duty emails that get verified before they make it to the marketing list.
  • Clearout also removes duplicate emails, verifies if recipients can accept new emails, and has spam detection algorithms.


3. NeverBounce:

  • NeverBounce can verify large lists; cleaning an email list is very simple. All one has to do is connect the email provider with NeverBounce.
  • Including NeverBounce in your mail marketing process will enhance the deliverability rate as the email list will always be accurate.


Improved Deliverability Achievable With Warm-Up Tools

If you want to prevent your email from landing in spam, an email warm-up tool is necessary. Besides, warming up email helps it to gain a reputation for your IP. So, if you have an email you haven’t used in a while, or if you have a new one, warm it up. Here are the tools that can help you do that.

1. lemwarm by Lemlist

  • Part ways with your spam folder with lemwarm by Lemlist. With lemwarm by Lemlist, no more sending and responding to emails with fake accounts.
  • lemwarm by lemlist runs a trade-off policy with 20,000+ people in over 100 countries. As the senders esteemed, the email reaches the right inboxes.

lemwarm by Lemlist

2. MailReach

  • MailReach is also involved in the email trade of programs, henceforth maintaining a high reputation for our brand with Outlook and Gmail.
  • Marketers also use MailReach to land their emails in the primary inboxes, which generally end up landing in the promotion folder or spam. To back up the ability of MailReach, it comes with an intuitive dashboard that provides live updates about the warm-up status.


3. Folderly

  • It is an AI-powered email warmer whose primary job is to solve, identify, and maintain all issues related to email deliverability. Using Folderly simplifies marketers’ tasks as it is easy to set up, track, and monitor.
  • Other email marketing solutions come along with this tool: email placement test, SPF generator, and deliverability audit.


4. Auto-Warmer by QuickMail

  • The best part of the Auto-Warmer tool is the free-forever plan. However, the free program has certain limitations. The free version is only functional for three types of inboxes: Outlook, Gmail, and SMTP.
  • Upgrading to the paid version is a must to get hands on the warm-up deliverability report. If you can be flexible on your budget, more functionalities are available.

Aut Warmer by QuickMail

A/B Testing Tools

A/B testing is one of the most noteworthy methods to study the effectiveness of email elements like CTA, personalization, body copy, and subject lines. When strategized the right way, A/B testing won’t only improve the conversion rate, but it will also increase the open rates. To unlock its optimal effectiveness, marketers must decide on one element, sample size, and the number of versions to test. Below are the list of tools that heightens the performance of A/B testing.

1. Optimizely

  • Optimizely is an outstanding A/B testing tool for checking the significant elements of email.
  • It has numerous digital experience tools for content management, marketing, and planning.
  • Lastly, marketers enjoy the functionality of Optimizely as it has the capability of multivariate analysis.


2. Mailchimp A/B Testing Software

  • A lot of customization is possible with Mailchimp A/B testing software. Marketers can pick the variable they want to test, set the percentage of recipients for the test, determine the parameter for winning a variant and lastly pick the variable they want to try.
  • Premium Mailchimp A/B testing software users can implement the A/B testing in eight more combinations.


Table for referring to the key features and pricing of the above-mentioned email testing tools

Email testing tool Key features Pricing
Litmus Pre-send spam testing, integration with 20+ apps, email, phone, and chat support, email preview of 100+ email clients $99-$199 per month for 1-5 full users
Mailtrap Spam testing, access to Mailtrap API, detailed information about email headers, safe email testing with a fake SMTP server, Free-$299 per month
Email on Acid Unlimited email previews, spam or deliverability checks, full content checking of links, images, and spelling, commenting access, email and chat support $99-$599 per month for 1-10 users
Email Preview Service Advanced HTML editor, unlimited email previews, variable email spam and inbox testing, identification of spam issues $25-$399 per month for 1-10 users
SendForensics Email client preview testing, live inbox placement testing, predictive deliverability score, DMARC compliance verification, blacklist and whitelist monitoring $49-$199 per month for 2-10 users
GlockApps Bounce analytics, Email spam tests, DMARC messages, Email template editor, IP reputation monitoring $79-$129 per month for 1-5 users
ZeroBounce Integrates with 40+ apps, unknown results are free, 24/7 customer support, IP address geolocation Pay-as-you-go or $39-$249 per month, 100 free monthly validations
Clearout Gibberish check for identifying random email addresses, integrates with 100+ apps, duplicate email removal, greylisting verification, blacklist monitoring Pay-as-you-go or monthly pricing, 100 free monthly validations
NeverBounce API access, custom list tagging, bulk list email cleaning, automated list cleaning, integrates with 80+ apps Pay-as-you-go or monthly pricing
lemwarm by lemlist Real people, no fake accounts, warms up any email domain, 25+ years domain age range $25-$29/month
MailReach 12,000+ real inboxes, email reputation monitoring, email monitoring dashboard, live blacklists and DNS checkups $25 per email account per month for one to five email accounts
Folderly AI-based email warmer, email deliverability audit, email placement test, SPF Generator $49 per month
Auto-Warmer by QuickMail Tracking of email opens and clicks, automated stop on reply, automated follow-ups, bounce detection, live notifications, A/B testing Free-$79 per month and per inbox
Optimizely API access, win rate reporting, email split testing, collaboration within the Optimizely platform, knowledge base and academy support Pricing undisclosed, contact sales team
Mailchimp A/B testing A/B testing, multivariate testing, segmentation, integration with 200+ apps, knowledge base, email $13-$1000+/month depending on number of contacts

As email marketing is still a convoluting feature when marketing is considered, investing in an email testing tool aligned with the niches of your desired results is beneficial. After that, working on tech trends in email that can give you a foothold in a competitive market is an exciting domain to focus on, as it can drive revenue.


Gone are the days in marketing when you can throw a dart in the dark. With email testing tools, potential obstacles, the nitty-gritty of inbox placement, and precision in reaching the right inboxes can be achieved seamlessly. To sum it up, email testing tools can assist in maintaining email list hygiene, and it will eventually reap a remarkable email campaign success.