How to Use Email Testing for Manual and Auto-Process Tests

Our recommended method for generating email previews is our Campaign Precheck tool. With this option, you can confirm that your email meets accessibility requirements, the images are properly formatted, the URLs are valid, and more. Using Campaign Precheck results in the best campaign possible. We do offer another manual tool, Email Testing, if you need to run a quick set of previews. You can start a manual test, or send your test from your email service provider (ESP) to your Email on Acid projects.

Running a Manual Test

If you have your code available in a URL, a ZIP file, or you want to copy and paste from a document you can run a manual test by following these steps:

  1. Click on Email & Spam Testing on the navigation bar.
  2. Click Email & Spam and click Next.

  3. Enter the URL, copy and paste your HTML, or browse for and upload your ZIP file.
  4. Your test will default to All Previews, but if you have created a custom client profile you can choose it from the dropdown list. Learn how to build a custom client profile
  5. Enter the Subject Line and click Next.
  6. Select the preferred method to send the spam test if you would like to include a spam test with your previews. Learn more about how to complete the spam test in the Email on Acid platform.
  7. Click Run Test.

Run a Test From ESP

You can also send your project from your ESP to your Email On Acid projects page, and this is highly recommended to check if your ESP is changing anything in your code upon send.

To find the email address to send to:

  1. Click on Email & Spam Testing on the navigation bar.
  2. Click Email & Spam and click Next.

  3. The email address you will use to send from your ESP to Email on Acid will be displayed. If you have a custom client list it will have a unique email address assigned, and you can locate this by clicking on the dropdown Email Client Profile.

  4. Send the email from your ESP, and then click on Projects on the navigation bar to locate and review your project.

Some best practices for sending from an ESP include:

  • Never forward an email to this address. This will result in potential issues with previews.
  • Do not send more than one email at the same time. This can cause previews to not load correctly. Send each email at least 1 second apart.


You will have 2 or 3 result tabs, depending on whether you chose to run a Spam test. There are tabs for Email Test Summary, Deliverability, and URL Validation.

Email Summary Tab

Your previews will be displayed here, and you can click through them to verify that each one displays as you intend. You can change the thumbnail view by clicking the dropdown.

You can share your test results with others for review. To learn more about sharing your results, click here.

Under Tools you will see:

  • Inline CSS
    Applies unique styles to a single element in your code
  • Text Only Version
    Displays the email in text only
  • Preview HTML
    Shows the HTML code, but does not allow for editing
  • Download
    Select the previews you would like and create a zip file


If you ran spam test with the previews, you will see your results here. Spam results can take time to return, so please allow up to 10 minutes. To learn more about spam testing and results follow these resources:

If your results don’t return, or you have further questions, send your share link to and our support team will help!

URL Validation

URL validation will check each URL and let you know if there are any issues accessing the links. If you receive an error, check the link to make sure it is working prior to sending your campaign.