HTML email tester

Learn how HTML email testing can complement your email marketing strategy and drive best-in-class email deliverability.

Test email across devices and email clients

Whether your customers receive email on a mobile device or on their computer at home, developers and marketing teams want to make sure their emails look good. The internet and technology changes so rapidly that even the savviest developers cannot guarantee that their HTML email will format correctly across all platforms. From cell phones, tablets, laptops, and desktops, to popular email clients such as Google,, Yahoo, Apple Mail, AOL, and more, there’s too much to keep track of to manually test email. HTML email testers enable teams to quickly and easily test the look and design of their emails across multiple devices and different email clients.

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Include HTML email testing as part of your larger email strategy

To optimize the delivery and performance of email marketing and transactional emails, HTML email testing is one of several important considerations. Email delivery platforms also provide tools that ensure you’re sending to real email addresses, enable A/B testing through segmentation, provide analytics or a campaign monitor, and more.

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Automatically Validate Email Addresses in Real-Time

Before sending an email, the best way to protect your sender reputation and ensure email deliverability is to ensure that the email addresses that you receive are legitimate. With Mailgun’s email verification API, you can integrate validation directly into your web forms to take advantage of our custom grammar checks for Gmail, Hotmail, and Yahoo, and catch typos such as ‘’.

Use Tags and Segmentation to A/B Test

Another important way to test and optimize emails is to A/B test different variations and optimize accordingly. With Mailgun, tags make it possible to A/B test your messages, compare variants to one another, and determine the winner. Through the use of tags, you can experiment with button placement, call-to-action text, color, font sizes, or anything else you might wish to split test in your emails. For example, with a password reset email you could use tags of “password-reset” and “password-reset-var2” to easily review analytics for each email separately.

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Track critical email delivery metrics

Whether you’re testing HTML emails, A/B testing different email variations, or running other types of tests, your email service needs to have a strong campaign monitor and analytics tool that helps surface insights that you can use to optimize performance. At Mailgun we offer free analytics tools that surface key metrics and insights that you can act on.

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Sending over 100,000 messages per month? Sign up for a free account or check out our plans to bundle together features for better deliverability.

Check out our plans to bundle together features for better deliverability. For businesses that send over 100,000 emails.

Other features

Explore beyond HTML email

Mailgun has a variety of features for companies to test HTML email.

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Use Cases

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