The Ultimate Guide to Testing Newsletter: Best Practices and Tools

The Ultimate Guide to Testing Newsletter: Best Practices and Tools

In today’s digital world, email newsletters remain a powerful tool for businesses to connect with their audience, promote products and services, and build brand loyalty. But simply sending out a newsletter isn’t enough. To ensure your message resonates with your subscribers and achieves your marketing goals, testing newsletter before sending it out is crucial. This guide will equip you with the knowledge and tools to become a master of newsletter testing.

Why Testing Newsletter is Crucial

Think of your newsletter as a salesperson meeting a potential customer for the first time. A well-tested newsletter, free of errors and optimized for engagement, creates a positive first impression that lays the groundwork for a lasting relationship. Here’s why testing matters:

  • First Impressions: A poorly designed or irrelevant newsletter can damage your brand reputation and lead to unsubscribes. Testing ensures a professional and engaging experience. Imagine receiving an email with typos, broken images, or text that’s difficult to read. It wouldn’t inspire much confidence in the sender, would it? Testing helps you avoid these pitfalls and presents a polished, professional image that reflects well on your brand.
  • Avoiding Mistakes: Typos, broken links, or poorly formatted content can hurt your credibility and make you look unprofessional. Testing helps catch and fix these issues before they reach your audience. A single typo in a critical offer or a broken link leading to a dead page can leave a bad taste in your subscribers’ mouths. Testing allows you to iron out these wrinkles and ensure your newsletter delivers a flawless user experience.
  • Enhancing Deliverability: Spam filters are becoming increasingly sophisticated, and poorly designed emails can get flagged and sent straight to the spam folder. Testing helps ensure your newsletter lands in the inbox, not the spam folder. Spam filters look for red flags like excessive use of exclamation points, misleading subject lines, or large image sizes. By testing your content and design, you can avoid these triggers and increase the chances of your newsletter reaching its intended audience.
  • Maximizing ROI: Every aspect of your newsletter, from the subject line to the call to action, impacts its effectiveness. Testing allows you to optimize each element for maximum impact, ultimately leading to a higher return on investment (ROI) for your email marketing efforts. By testing different versions of your content and design, you can identify what resonates best with your audience and drives the most clicks, conversions, or sales.

Key Elements to Test in Your Newsletter

Every part of your newsletter plays a role in its success. Here are some key elements to put to the test, along with some specific details to consider for each:

Subject Lines

Your subject line is prime real estate, with limited space to grab attention and entice subscribers to open your email. Here’s what to test:

  • Emojis: Emojis can add personality and stand out in crowded inboxes, but use them sparingly and ensure they are relevant to your content.
  • Personalization: Including the subscriber’s name or location in the subject line can personalize the message and increase open rates.
  • Questions: Questions can spark curiosity and encourage subscribers to open the newsletter to find the answer.
  • Urgency: Phrases like “Limited Time” or “Don’t Miss Out” can create a sense of urgency and prompt immediate action.
  • Numbers: Numbers can grab attention and highlight specific benefits or discounts.

Design and Layout

A visually appealing and user-friendly layout keeps subscribers engaged. Test these aspects:

  • Responsiveness: Ensure your newsletter displays correctly across different devices (desktop, mobile, tablet).
  • Scannability: Break up text with images, subheadings, and bullet points for easy reading.
  • Mobile-first approach: Since many users check email on their phones, prioritize a mobile-optimized design.
  • Color scheme: Test different color combinations that align with your brand identity and promote readability.
  • Image placement: Experiment with where to place images for maximum impact and visual flow.

Content and Copy

High-quality content is key to keeping subscribers engaged. Here’s what to refine:

  • Target audience: Tailor your content to the specific interests and needs of your subscriber segments.
  • Writing style: Test a formal vs. informal tone to see what resonates better with your audience.
  • Content length: Experiment with different content lengths (short snippets vs. long-form articles) to find the sweet spot that keeps subscribers interested without overwhelming them.
  • Personalization: Use subscriber data to personalize the content with their names, purchase history, or website browsing behavior.

Call to Action (CTA)

A clear and compelling CTA tells subscribers exactly what you want them to do next. Test these aspects of your CTA:

  • Clarity: Use strong verbs and concise language that leaves no room for confusion.
  • Placement: Experiment with CTA placement throughout your newsletter (beginning, middle, end) to see what drives the most action.
  • Button design: Test different button colors, shapes, and sizes to see what gets the most clicks.
  • Sense of urgency: Consider adding limited-time offers or discounts to incentivize immediate action.

Images and Multimedia

Visuals can significantly enhance your newsletter, but use them strategically. Here’s what to consider:

  • Image Size and Quality: Use high-quality images that are optimized for fast loading times, especially on mobile devices.
  • Alt Text: Include descriptive alt text for all images to improve accessibility and SEO.
  • Video Previews: If using videos, test including short video previews with clear play buttons to entice clicks.


Broken links can be a major frustration for subscribers. Here’s how to ensure smooth navigation:

  • Test All Links: Before sending, thoroughly test every link in your newsletter to ensure they direct users to the intended pages.
  • Shorten Links: Consider using link shorteners to create cleaner-looking newsletters and track click-through rates.
  • Length: Keep it concise (ideally under 50 characters) to avoid getting cut off in inboxes.
  • Clarity: Make it clear what your newsletter is about, but avoid sounding spammy.


Include subscriber names or locations to personalize the experience and boost open rates.

  • Urgency or Curiosity: Create a sense of urgency with time-sensitive offers or pique curiosity with a question or intriguing statement.
  • Emojis (optional): Test with and without emojis to see what resonates with your audience, but use them sparingly to avoid appearing unprofessional.

By testing these various elements, you can optimize your newsletter for maximum impact and ensure it resonates with your target audience.

Tools for Testing Your Newsletter

The good news is, there are plenty of tools available to help you with newsletter testing, catering to different needs and budgets. Here’s a look at some popular options:

  • Email Testing Platforms: Tools like Litmus and Email on Acid go beyond simple previews. They allow you to render your newsletter across a vast range of email clients and devices, including desktop programs (Outlook, Apple Mail), webmail services (Gmail, Yahoo Mail), and mobile apps. This ensures a consistent user experience regardless of how your subscribers access their email. Some platforms even offer spam testing and feedback on coding best practices to further optimize your newsletter’s deliverability.
  • A/B Testing Tools: A/B testing lets you compare different versions of your newsletter elements to see which ones resonate more with your audience. This is particularly useful for crafting compelling subject lines, optimizing call-to-action buttons, or testing different design layouts. Many popular email marketing platforms like Mailchimp and Constant Contact offer built-in A/B testing functionalities, allowing you to set up tests directly within your email creation workflow.
  • Spam Checkers: Tools like SpamAssassin and IsNotSpam act as your safety net before sending. They scan your newsletter content and code for elements that might trigger spam filters. This includes analyzing things like excessive use of exclamation points, spammy keywords, or low text-to-image ratios. By identifying and addressing potential red flags, you can significantly increase the chances of your newsletter landing in the subscriber’s inbox, not the spam folder.
  • Analytics Tools: Platforms like Google Analytics and built-in analytics from your email marketing service provide valuable insights into how your newsletters are performing after sending. These tools track metrics like open rates, click-through rates, unsubscribe rates, and even geographical data on where your subscribers are opening your emails. By analyzing this data, you can identify areas for improvement and tailor your future newsletters for better engagement and results.

Best Practices for Newsletter Testing

Here’s how to take your newsletter testing to the next level:

  • Start Small and Specific: Don’t overwhelm yourself by testing everything at once. Choose a single element, like a subject line or call to action (CTA), and create a few variations to test. This allows for focused analysis and avoids confusing results.
  • Define Success Metrics: Before testing, determine your goals. Do you want to increase opens, clicks, conversions, or brand awareness? Knowing your success metrics helps you choose the right elements to test and interpret the results effectively.
  • Statistical Significance: Don’t be fooled by small victories. When testing different variations, ensure you have a statistically significant sample size. This helps avoid drawing conclusions based on random chance and gives you a clearer picture of which version truly performs better. Many email marketing platforms offer built-in calculators to determine statistically significant results.
  • Control Group: Always include a control group in your A/B testing. This is the original version of your newsletter that serves as a benchmark for comparison. Analyzing how your variations perform against the control group reveals which elements are driving positive change.
  • Test Across Devices: Modern audiences access email on various devices like desktops, tablets, and smartphones. Ensure your newsletter renders correctly and looks good across different screen sizes and email clients. Many email testing platforms offer device previews for comprehensive testing.
  • Personalization is Key: People respond better to messages that feel relevant to them. Consider testing personalized elements like subscriber names or content based on past purchases or website behavior. This can significantly boost engagement and click-through rates.
  • Test Preheader Text: The preheader text appears next to the subject line in many email clients and gives subscribers a sneak peek of your content. Craft compelling preheader text alongside your subject line to further entice readers to open your newsletter.
  • Test Landing Pages: Don’t stop testing after your newsletter gets opened. Make sure the landing pages linked within your newsletter are optimized for conversions. A/B test different landing page elements to ensure a smooth user experience and maximize the return on your email marketing efforts.

Beyond the Basics:

While subject lines and CTAs are crucial, there’s more to explore. Consider testing the following:

  • Content Length: Do subscribers prefer short and sweet updates or more in-depth articles? Test different content lengths to see what keeps them reading.
  • Content Format: Does your audience respond better to text-heavy content, or do they crave visuals like infographics and videos? Experiment with different content formats to find the right mix for engagement.
  • Sender Name: Should your newsletter come from your company name or a specific person? Test different sender names to see which one resonates best with your audience.

Segment Your Audience

Don’t send a one-size-fits-all newsletter. Segment your subscribers based on interests and demographics to test content that resonates with each group. Go beyond basic demographics and consider factors like purchase history, website behavior, and engagement level. For example, test a discount offer for a new product line with subscribers who have previously purchased similar items.

Timing and Frequency

When is the best time to send your newsletter? How often should you send it? Test different sending times and frequencies to find the sweet spot that maximizes engagement. Analyze open rates and click-through rates based on sending times throughout the week and day. You might discover that Tuesdays at 10 am work best for your audience, while Wednesdays at noon have lower engagement.

Continuous Improvement

Testing is an ongoing process, not a one-time event. Regularly test different elements and analyze results to continually improve your newsletter performance. Don’t just test once and forget it. Set up a regular testing schedule, perhaps quarterly or bi-annually, to revisit key elements and see if there’s room for further optimization. Make data-driven decisions based on your findings.

By following these best practices, you’ll gain valuable insights from your newsletter testing and create campaigns that resonate with your audience and achieve your marketing objectives.


Remember, testing is your secret weapon in the world of email marketing. By following these guidelines and utilizing the available tools, you can create newsletters that drive engagement, build stronger relationships with your audience, and achieve your marketing goals. So, don’t wait – start testing your newsletter today and see the results for yourself!

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