My email looks different when viewed in Microsoft Outlook

You will learn

Learn why some emails look different in Microsoft Outlook than other inboxes, as well as tips for improving consistency in how your messages render in Outlook.

Outlook's rendering engines

Classic Outlook for Windows uses Microsoft Word to display emails. Other versions, including new Outlook for Windows, Outlook for Mac, and Outlook.com, use browser-based rendering engines. This means the same email can look different across Outlook versions.

Consider the last time you tried to make edits to a table or resize an image in Microsoft Word. The formatting challenges you face when using Word are similar to the challenges faced by emails in Outlook inboxes.

Because of this, an email may look slightly different in Outlook than when you initially design and preview in Klaviyo.

If you choose to optimize your emails for Outlook, use Klaviyo's built-in inbox testing (available for paid accounts) to preview your messages on various devices and inboxes.

Optimize your emails for Outlook

In versions of Outlook that use Microsoft Word to display emails, you may see the following issues:

• Background images in divs and table cells not supported or shown
• CSS float and position elements ignored
• Text shadow not supported or shown
• Unusual padding and margin, due to poor support for these elements
• CSS width and height not shown as intended, due to poor support for these elements
• Nested elements’ background colors shown incorrectly or ignored

Optimizing an email for Outlook can take time and testing. Changes to image positioning can affect how your email renders in other email clients and on mobile devices, so test your design across the inboxes your audience uses.

Sizing images for Outlook

If an image appears stretched or oversized in Outlook, set its display width in your template:

1. Select an image block.
2. Add a number to the Image layout > W field. For full width images, use 600 px (or whatever width your email is set to, found in the Styles section).
   

3. Save your changes.

GIFs in Outlook

GIF animation support varies by Outlook version. Some versions show only the first frame as a static image. Include your key message in the first frame so it still makes sense without animation.

Understand Outlook’s impact on your audience

To see which email clients Klaviyo detected for a recently sent campaign:

1. Navigate to the Campaigns tab in Klaviyo.
2. Find a recently sent email campaign. If its row is expandable, expand it and click the sent email message's name. Otherwise, click the campaign name.
3. Click the Deliverability tab of the email's report.
4. Review the Performance by email client section and look for Outlook entries under Desktop opens.

The percentages are based on unique opens from recognized email clients, rather than your entire recipient list. Unknown clients are excluded, and browser or mobile opens may not identify Outlook by name. Use this breakdown as a guide when choosing which inboxes to test.

Additional resources