Working together to #MakeEmailBetter

Litmus + Microsoft Partnership

See the exciting announcement

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Litmus and Microsoft team up

Litmus and Microsoft are teaming up to make email better for thousands of email marketers—and the hundreds of millions of people who use Microsoft email products. Together we prioritize known Microsoft email rendering bugs, identify issues faster, and announce improvements and fixes to the community.

Submission form

Rendering bugs feedback loop

The email community can now participate in the world’s first email design feedback loop. Litmus collects bug reports and rendering issues directly from Checklist, helps to prioritize them, and reports all findings directly to the Microsoft team. In close cooperation with Microsoft, we work to fix bugs and announce their resolution to the community.

You can also submit feedback and rendering bugs to

Available for:

  • Outlook (iOS)
  • Outlook (Android)
  • Outlook 2016
  • Outlook for Mac 2016
  • Windows 10 Mail
  • Office 365

Rendering updates and bug resolutions

Brought to you by the Microsoft-Litmus partnership.

Jun 19

Litmus launches Email Previews for Outlook 2019 120 DPI. See a full list of all email clients available in Litmus Email Previews.

Oct 18

Litmus launches Email Previews for Outlook 2019. The new version of Outlook comes with SVG support and no longer uses Times New Roman as a fallback for web fonts. Learn more →

Mar 18

Media Query support fully returns for Outlook on Android. Outlook’s Android app now supports media queries with the latest version 2.2.114 (or above) installed.

Feb 18

Litmus launches Email Previews for Outlook on iOS. See a full list of all email clients available in Litmus Email Previews.

Jan 18

Media query support fully returns for Outlook on iOS. The Outlook team is working on bringing media query support back to the Outlook Android app.

Jan 18 now supports background images. Adding CSS background image support to Outlook was the #1 feature request the email community submitted via the Litmus-Microsoft feedback loop. We’re excited to share that both and Office 365 now support CSS background images. Learn more about background image support in in our 2018 State of Email Report.

Nov 17

Litmus launches Email Previews for Outlook on Android. See a full list of all email clients available in Litmus Email Previews.

Oct 17

Due to rendering issues in some edge cases, Microsoft had to temporarily turn off media query support for its mobile apps.

“After release, we identified some edge cases where incorrectly formatted emails were not rendering properly. We have temporarily turned off media query support to ensure that these emails get rendered correctly while we release an update to become more tolerant of minor coding errors.”
Kate Everitt, Microsoft Outlook
Sep 17

Microsoft and Litmus announce that media query support are returning to Outlook’s iOS and Android apps. Learn more →

Jul 17

Windows 10 Mail now supports animated GIFs. Previously, Windows 10 Mail would show only the first frame of the animated GIF, which would appear as a static image. Learn more →

These updates and improvements were made possible thanks to the feedback we’ve received from the email community.

111 bugs reported:

  • 11 Outlook iOS
  • 6 Outlook on Android
  • 24 + Office 365
  • 50 Outlook (Windows)

On topics:

  • 11 bugs submitted related to fonts
  • 9 bugs submitted related to background or background images
  • 8 bugs submitted related to links / buttons
  • 7 bugs submitted related to DPI scaling
  • 6 bugs submitted related to horizontal white lines
  • 4 bugs submitted related to media queries

Microsoft email clients available for testing in Litmus

Microsoft is working with Litmus directly to provide access to even more of their email apps, so you can test your emails in popular Outlook environments and fix rendering issues before you send.

Sign up to receive the Litmus newsletter and updates about the partnership

Frequently Asked Questions

How does reporting an issue work?

Litmus has integrated a feedback mechanism directly inside its product. When viewing an Email Preview of an Outlook client in Litmus Checklist, users will have the ability to submit a bug in-app. Litmus will forward the incident, including its screenshot and HTML source code, to the Outlook team. Users can also submit bugs via email to

Is there a timeline on when issues will be fixed?

Outlook will review all issues and prioritize key issues. No timelines or public roadmaps will be available on what rendering changes are being worked on, but Litmus will communicate any such changes.

How will we find out about updates from Microsoft?

When any rendering change or update is made to Outlook email clients, Litmus will communicate such changes to the email community. Be sure to sign up for email updates, follow Litmus on Twitter, and read the Litmus blog.

How quickly will updated versions of Microsoft products be available in Litmus testing?

As a part of this partnership, Outlook and Litmus have a direct line of communication. Outlook engineers will be working with Litmus to ensure we have access to the most up-to-date Outlook email clients. If any updates to existing clients are made or new Outlook clients are launched, Litmus will provide access to the most popular versions of these email clients (based on usage).