We regularly test these email clients using internal test tools and Email on Acid.

All the options work properly. Fallback elements show for web fonts.

Desktop
Apple Mail 12 & 13

Microsoft Outlook for Mac 2011, 2016
Microsoft Outlook for Windows 2010, 2011, 2013, 2016, 2019*
Thunderbird
Airmail2

* Web fonts are not supported

Mobile

Android: Pixel Gmail Android 6, 7, and 8
Samsung Mail Android 7
Gmail App (iOS)
Gmail App (Android)
iOS Mail (iPhone & iPad)
Outlook App (Android & iOS)
Yahoo App (Android & iOS)

Web

Gmail

G Suite
Inbox by Gmail
Outlook.com
Office 365
Yahoo
AOL Mail
Comcast
freenet.de
GMX.de (web version)
Mail.ru
Libero Mail
Tiscali
Virgilio
email.it
Web.de (web version)
Centrum.cz
Seznam.cz, Post.cz, Email.cz

Note: none of the above services supports web fonts

Messages display correctly, but some options (with low impact) may not display as expected.

Desktop

Microsoft Outlook 2013 in high-resolution displays *
Microsoft Outlook 2016 in high-resolution displays **
Microsoft Outlook 2000, 2002 & 2003 ***

*Web fonts are not supported. Applies a font resize that may expand the layout.

** Web fonts are not supported. Applies a font resize that may expand the layout. The text is scaled at 200% by default in some devices.

*** Web fonts are not supported. Buttons don't display round corners. Social icons are not flexible.

This list includes new and updated mobile email clients with compatibility issues.

Huawei Mail App (Android)

When sending to these clients, we recommend using text and images in a simple one-column layout.

Desktop

Lotus Notes 7, 8 & 8.5
Windows 10 Mail
IBM Notes 9

Mobile

Web clients (mobile versions)

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