You’ve worked diligently with your team and other departments to craft the perfect email message for the newest campaign. You’ve gathered engaging creative, drafted compelling copy, segmented the ideal audience, and aligned all of your customer preferences and data points. All of this work comes to life the moment you hit “send.”

Without a testing process and tools in place, the subscriber receiving the message as intended is a matter of closing your eyes and crossing your fingers. With the right testing setup, the end experience is no longer a guessing game, and one less worry to keep your team up at night. Understanding why to test, what to test, and how to test will give you the tools needed to ensure a better return on efforts and stellar customer experience.


What do we mean by “test?”

A quick moment of clarification, “testing” can mean different things to different people. In this blog post, we do NOT cover testing different creative against each other to determine which performs better (i.e., A/B or multivariate testing). If that is what you’re looking for, we have a couple of great posts to give you the skills you need. What we DO cover, is testing as part of a quality assurance process that ensures a message renders correctly in the subscriber’s inbox before hitting the send button.


Why test email messages before sending?

Most email marketing veterans have embarrassing stories of moments when emails didn’t go as planned — for example, when a subscriber received a “Hello [First Name]” salutation because the merge field wasn’t set up properly or a time when an email that wasn’t optimized for mobile was sent to a group of chief marketing officers.

If you look at email tests as a way to avoid pain, you can protect against moments like this. You will no longer have to guess how your email will appear to your subscribers because you test the content of your emails in different email inbox environments before you send them.

After a solid testing process is in place, testing not only helps you avoid bad experiences, it also becomes a strategic force to drive message optimization. As email marketing programs evolve, teams use more and more data to personalize at scale. This will give you l the foundation needed to ensure these elevated experiences are received as intended.

In short, testing provides peace of mind, avoids bad customer experiences, creates foundations for program growth, and ultimately diverts the need from learning from mistakes to learning while creating.

When you get started there are a couple of email aspects you should test and how you should go about doing it.

1. How the email looks in different email clients

From Gmail to Outlook, countless mobile apps and international webmail clients, your subscribers can choose between hundreds of email clients — and each of them displays your HTML email a little differently. The email that looks perfect on your iPhone’s Mail App might be broken for subscribers who open it on Outlook. Without a testing process that lets you preview messages in the most popular reading environments, you risk sending broken emails to your audience.

When testing how email appears in various email clients, keep in mind:

  • The top 10 email domains your subscribers use — test how your email looks in AOL, Gmail, Yahoo, Outlook, and the other most popular domains your subscribers use to make sure you cover your bases.

  • The top 10 devices your subscribers use to check emails — test how your email appears on smartphones, laptops, and desktops to make sure your emails look great across multiple devices.

Pro Tip: Ensure the email client your company uses is on your list. You want to ensure everyone in your organization (including your boss) has a great email experience.

How to test the content of emails on various clients and devices:

  • Manually set up email accounts on different clients and send emails to yourself — this takes time and effort, but it’s a starting point.

  • Leverage tools built into your Email Service Provider (ESP) to test at scale — at Salesforce, we’ve partnered with Litmus to bring their best-in-industry testing capabilities directly into the Marketing Cloud user interface. From the preview tab, you can click into Litmus and automatically see how your message appears across any email client.

2. Ensure personalization is set up correctly

Your goal is to avoid data errors and personalization strings where code appears in the message instead of the personalization token — for example, “Hi [First Name]” instead of “Hi, Shannon.”Each customer should receive the images, copy, and personal information intended specifically for them.

To ensure personalization is working:

  • Make a list of all the personalization fields you use — you might include account number, first name, company name, purchase history, or images that update based on actions your customer has taken on your website; this will be your quality assurance (QA) checklist and should include any variables that will determine if a field changes for an individual.

  • Understand your data — have a clear picture of which data points power the different areas of personalization and troubleshoot for errors. If you notice the images don’t change based on customer interest as intended, make sure you know what you need to update or cross-reference to make the correct edits.

How to test personalization fields:

  • Send test emails to yourself or to a small internal audience to see how the different data points and personalization fields display — it’s time-consuming and requires a solid QA process to ensure all areas are checked, but it works as a baseline.

  • Use tools to preview the subscriber-level experience — Marketing Cloud has subscriber-level previewing built directly into the user interface to help keep track of the personalization experience you’ve mapped out for every subscriber and ensure it’s working appropriately.

Pro Tip: Testing is just one element to consider as you scale your email program. Want to know more about what it takes to successfully send email at scale? Check out this webinar to learn about the people, processes, and tools required for a best-in-class email program.

Every successful email program has a testing process in place. Whether you’re starting and going the manual route or taking advantage of tools built into your ESP for scale, you’re building the foundations for a best-in-class subscriber experience. 

Check out our 50 Email Best Practices ebook for more great email marketing tips you can use.