Email Testing

Email campaigns are a great way to communicate with a large audience through different platforms and devices. They are an effective marketing method that can reach a large number of people. A well-executed email campaign can have a positive impact on business performance overall. It can boost sales and customer retention, which can lead to improved results in the long term. Email testing is an important way to improve your email campaign efficiency by understanding how it works and why it's important. There are different types of email testing you can use to determine the effectiveness of your email campaigns.

What is Email Testing?

Email testing is a process of inspecting your email to see which aspects are working well and which can be improved. This can help you to optimize your key performance indicators (KPIs), such as open rates and click-through rates. Email testing is a great way to improve the quality of your email content, as well as the delivery and rendering of your emails. By testing different subjects, messages, and subject lines, you can find which ones best resonate with your readers. With email testing, you can ensure that your email arrives the way you intended on different devices, operating systems, browsers, and other software. It's important to test your email before sending it to a large number of recipients. Make sure any included images, graphics, and links work properly. The grammar checker also helps you to review your written content to fix any spelling or grammar errors.

Importance of Email Testing

If you make a mistake on your website that causes your visitors to get lost or confused, it could damage your business. A mistake like sending your subscriber to the wrong landing page can have a negative impact on your ROI. Email errors can damage your reputation with your subscribers. If they perceive that your emails are not being sent correctly, they may not trust you and may stop reading your messages.

There are a few factors that can affect the success of your email campaign. Some of these factors include the content of your email, the timing of your email, and the reach of your email. Some of the factors that can affect the effectiveness of an email campaign include the content, design, and layout of the emails, as well as the way that the email is marketed. Email marketing is an effective way to connect with your customers and build relationships. By testing different email campaigns and content, you can ensure that your messages are reaching your target audience and driving results.

What to Test in an Email?

There are a few things to consider when testing an email campaign: content validity, campaign parameters, and technical validation. Each one is important in helping ensure the campaign is successful.

Content Validity

Subject Line

Subject lines are critical to the success of your email campaigns. Your email's opening line could make or break its success. Make sure it's effective and influential. If you want to improve your writing, start by focusing on making your sentences as catchy and valuable as possible. This will help you to engage your readers and keep them interested in what you have to say. To know that your email subject line is working, test for higher open rates, and look for indicators that suggest a higher level of engagement from your audience. These could include higher click-through rates, higher conversion rates, or more positive feedback from customers. Things that should be tested for the subject line are;

  • Length
  • Personalization
  • Tone (formal or informal)
  • Optimization for different devices,


The preheader text is the introductory text that appears before the body of your email.  Appears on the first line of the email, just below the subject line (or next to it on the desktop). This is a subject line driven, providing context to what the email is about. If you want to boost your open rates, include a preheader text in your emails. This introductory paragraph can set the tone for your email and make it more appealing to recipients. They set the tone for what a subscriber can expect when they open the mail. Things you can test in the preheader are;

  • Inclusion (whether you include a preheader or not)
  • Content (topics of your preheader)

Call to Action

The CTA (or call to action) is a key element of most email campaigns and is often the focal point of each email, which is why it's important to make it stand out. Things that you can test in CTA are;

  • Design (color, font, shape, etc.)
  • Placement (bottom or top)
  • Size of the CTA button

Campaign Parameters

Email Time

To be more productive, it is important to test your email scheduling time to see where you can cut back. By doing so, you can ensure that you are getting the most out of your day. Testing email scheduling time can help you understand how your audience responds to CTA's at different times of the day. By understanding when they're more likely to act, you can create more effective email campaigns.

Email Date

To see the effect of changing your email scheduling days, test your open rates and CTRs over a period of several weeks. Both email scheduling days and times need to be tested regularly to find the best balance of open rates and click-through rates. There is no definitive answer to this question as it can vary depending on the season, business, and location.

Technical Validation


The way you present your website to your visitors is key to getting more conversions. Your email design and layout determine whether your subscribers scroll down and click your CTA. Keep your email design and layout updated to improve the user experience and click-through rates.

HTML and CSS Validation

There are many factors that can affect how email is rendered, including email servers, operating systems, screen sizes, images, apps, and web-based email clients. The HTML code in an email can vary depending on the device it's being viewed on. Some reasons include the device's capabilities, the email's format, and the email's sender. Since most marketers use responsive email builders, few think about testing and validating the HTML code.

Font, Link, and Image Validation

One of the ways your email's design can negatively affect your viewer's experience is by having broken links and blocked images. A broken link in an email is a costly error. If you produce content that's not up to par, your subscribers may be frustrated when they encounter errors or empty pages.

Types of Email Testing

You can run a series of manual email tests to determine specific design and formatting aspects across platforms, while email testing tools can automatically offer you certain types of tests, including:

  • A/B Test

A/B testing is a technique that allows you to compare the effectiveness of two different versions of an email or web page. By comparing the results of your test, you can determine which version is more successful. You can send the same email with a different subject line or with different media images to see which variant works best within the test group. These tests can help you improve future marketing campaigns by implementing the more successful variable. This information can help you create more successful campaigns that are more likely to achieve your desired results.

  • Spam Tests

To ensure your message is received by your target readers, one of the tests is the spam test. Email testing tools can check your message for spam and email blacklists, and can also help you determine if your IP address or domain name is on a list of banned addresses. You can improve your deliverability and open rates by identifying which specific issues are preventing your emails from being delivered or opening, and then learning how to address them. Testing your email content and subject lines is a great way to ensure they're spam-free and ready to be delivered to your recipients' inboxes. With spam filters in place, you can be sure that your messages are safe and clean.

  • Time Tests

To determine the best time of day to send your email campaigns, you can conduct an email test. This will help you to determine the best time of day to send your email messages based on how people are most likely to respond. By analyzing click-through rates for emails sent at different times, you can determine which times of day are the best to send emails and which links are most effective at getting users to open them. Time-tested email campaigns can be optimized by scheduling them at times when your subscribers are likely to be more responsive.

  • Preview/Design Tests

Images in email marketing can make a big difference in whether a campaign is successful or not. If an image is displayed correctly, it can help to create a positive impression with potential customers. Design tests can help you be confident that your email looks great, regardless of the viewer's environment. This can help you build confidence in your email's look and feel, which can lead to increased subscriber engagement. Ideally, all mailbox providers would render messages the same way. This would make it easier for people to find and use their messages. Different email clients have their own unique ways of displaying email. Outlook's desktop app looks great on desktop computers, but it can look different on iPhones and other mobile devices. Design testing is important to ensure your emails look good and load quickly, and that your most important content is shown above the fold. Design testing can help you identify and fix problems with your campaigns' look and subscriber experience. This information can be shared with your team so that we can make your campaigns even better.

  • HTML Tests

If your HTML contains elements that are tagged as spam, your sender's reputation may be harmed. Validating HTML code is important in conjunction with testing design elements, as it identifies issues like image file sizes, broken links, or suspicious code. If your email includes links to multiple websites, the test should be able to check if any of them point to prohibited domains that might raise spam alerts. There is no tool to verify that a link is actually landing where you intended, so it's still a good idea to check that the link is pointing to where you want it to land.

  • Subject Line Tests

To make sure your email messages are readable, make sure your subject lines and pre-header text are clear. This can influence whether or not subscribers open your messages. Subject line tests give you insight into how your text will look on different devices, giving you the chance to fine-tune your copy before sending it. A best practice is to create a subject line that contains about 45 characters, but it may still cut off some inboxes. The test shows where the preview text ends so you can create the message according to the importance of what you want to say to your reader.

  • Categorization Tests

Some email providers feature automated sorting of messages based on their importance, promotional, social, forum, and update status. By testing different sorting algorithms, you can increase the visibility of your emails, which could result in a higher click-through rate. Depending on your client base, you might classify your emails as important or promotional to ensure the best possible visibility.


There are a few things that can go wrong when trying to market your product or service, but there are also some great tools out there that can help make your campaigns more successful. Creating a real-time testing process is important because it allows you to take action that leads to better results, which ultimately leads to lower spam scores and happier customers.

Mailsoftly is one of the great email marketing software that allows subscribers to test their email campaigns with various testing options. Join now and explore Mailsoftly!