Design- and spam tests: Newsletter Client Testing

Display test for all common email clients

screenshot: Web clients, desktop clients, mobile clients, email programs, and web mailers.

Web clients, desktop clients, mobile clients, email programs, and web mailers. What do all these terms have to do with your campaigns? They are crucial when it comes to design and spam tests! This feature allows you to find answers to these two central questions:

  • How is your newsletter displayed in different email programs, web mailers or smartphones?
  • Do some of the email clients classify and block your mailings as spam?

Web clients: GoogleMail, GMX, Yahoo

Desktop clients: Apple Mail, Outlook, Thunderbird, Windows 10 Mail

Mobile clients: Apple (iPhone, iPad), Android, Google Mail App


1. Things you have to know

screenshot: What is spam?

What is spam?

Spam emails are sent without the recipient’s consent. Most of the time, they contain ads, but sometimes also dubious content. Unlike fake emails containing viruses, they are not dangerous, but annoying because of their frequency. More than half of all sent emails (some estimates go up to 90 percent) are nowadays considered spam. To protect recipients, email clients block junk mails and don’t let them reach the recipients’ inboxes.

That’s where the challenge begins: How can unwanted spam mails be blocked, and reputable newsletters be delivered? This is a task for so-called spam filters. These programs scan incoming emails and reject the ones that meet spam criteria.

How can the successful delivery of your mailings be guaranteed?

  • What CleverReach® does for you: server reputation

You’ve already done the first step towards a secure delivery of your newsletters: You chose CleverReach®! We make a positive server reputation and whitelisting of your mailings (high delivery rate!) possible through:

  • CSA membership
  • SPF
  • DKIM

These factors ensure that your mailings are not blocked or deleted as spam.

  • What you can do: Run newsletter spam tests before sending your mailing

Despite all these features, some mail clients could still see your newsletter as spam. To make sure they don’t, we recommend a design and spam test before you send your mailing. Run the test directly in your CleverReach® account. This test checks your email for all common criteria for spam classification.

2. Design and spam test settings

screenshot: cleverreach editor

After creating your newsletters, you should check if they look the same for all email clients. Go to “Preview & test” and find:

  • Virtual preview: see how your newsletter looks on a PC, smartphone and tablet
  • Test delivery: send your newsletter to your own email address and check if everything is as you want it to be
  • Design & spam test: this paid feature checks all available clients and filters.

Our design & spam test shows if your mailing is displayed correctly in all email clients and whether it’s regarded as spam:

  • Go to “Preview & test”
  • Click on “Design & spam test”
  • Buy your trial contingent directly via the button “Buy design and spam tests”.

Optionally, you can also get trial contingents in your account: “Account/Billing/Price plans”. First results are visible immediately. You’ll see views for all email clients. Zoom in to the images by clicking on them.

See the status of the test above the results. As long as the test is still running, not all email clients have been evaluated. You can keep working and run the test in the background if you like. You can download the results of the test as a zip file via the link “download results”.

3. Use your own or CleverReach® templates

screenshot: For the creation of your newsletters you can use

For the creation of your newsletters you can use

  • CleverReach® templates or
  • Your own templates

For both cases, we recommend running the design & spam test. HTML errors can easily occur in every programming! An inaccurate display of your mailing or erroneous links have a negative influence on your newsletter campaigns. If you notice errors after sending your newsletter, you can no longer correct them. The result of the test gives you the opportunity to optimize your newsletter before you send it to your subscribers.

4. Variables that influence the display of your newsletter

screenshot: To make sure that all email clients display your newsletter correctly, you’d theoretically have to set up an account with all providers and send your email to each account as a test.
  • mail client
  • device (PC, Smartphone, Tablet)
  • Browser
  • Operating system

To make sure that all email clients display your newsletter correctly, you’d theoretically have to set up an account with all providers and send your email to each account as a test. Additionally, you would have to open these emails on all possible devices and also in all different browsers and operating systems. That’s quite a number of possibilities you would have to check before sending your newsletter. The CleverReach® design & spam test does this job for you. One click, and it will quickly bring you all the results you need. This ensures that your mailing arrives your subscribers’ inboxes exactly the way you want it.

5. Tips & Tricks

  • Stick to our anti-spam regulations in your newsletters:To cause a positive test result, you should keep some guidelines in mind when creating your newsletter. Some elements, words and phrases are typical for spam emails, so make sure you avoid them. Potential spam indicators are:
    1. Tracking links that differ from the sender’s address
    2. Address that differs from the link description (might lead to phishing warnings)
    3. Use of certain words in the subject line (special offer, %, Viagra)
    4. Exclusive use of capitals or special characters in your subject line
    5. Image descriptions that are empty or susceptible to spam
    6. Don’t use too many images
    7. Irregular email delivery
    8. Attachments (that’s why you can’t send attachments with CleverReach®)
  • The CleverReach® design and spam test shows how your newsletter is displayed in various email clients on various devices. This gives you the opportunity to find programming errors and correct them. Still, every email client influences the display of your mailing. Small discrepancies are uncritical, as long as your newsletter is easy to read and displayed correctly.
  • There are more than 1,000 criteria to check – that’s why it takes some time to run the test.

Please note: The CleverReach® design and spam test is a paid additional feature, separate of your price plan.

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