Which email clients are supported?

We tested these email clients using internal test tools and email preview services as Email On Acid and Litmus.

Fully supported

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


  • Apple Mail 8, 9 & 10
  • Thunderbird
  • Airmail2
  • Microsoft Outlook for Mac 2011, 2016
  • Microsoft Outlook for Windows 2007, 2010, 2011, 2013, 2016 *
* Background images and web fonts are not supported


  • Android 4.4 Mail
  • Gmail App (iOS)
  • Gmail App (Android)*
  • iOS Mail (iPhone & iPad)
  • Outlook App (Android & iOS)**
  • Samsung Mail App (Android)
  • Yahoo App (Android & iOS)
* When using a Gmail account
** Will show the desktop version when using Microsoft email accounts


  • 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

Partial support for some options

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


  • Microsoft Outlook 2013 in high-resolution displays *
  • Microsoft Outlook 2016 in high-resolution displays **
  • Microsoft Outlook 2000, 2002 & 2003 ***
    * Background images and web fonts are not supported. Applies a font resize that may expand the layout.
  ** Background images and 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.


  • Huawei Mail App (Android) *
* Icons in social content block appear vertically stacked (tested on app version


  • qq.com *
  • Yandex.ru
  • Naver **
  * Buttons doesn't display properly.
** Minor glitches on separators

Not yet supported

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

  • Huawei Mail App (Android)

Only basic settings works

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


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


  • Gmail App using IMAP accounts
  • Web clients (mobile versions)


  • T-online.de

E-mail servers

Some email servers alter sent email code.

Server type

Code changes

WebDav / Deltasync protocols

Normal POP/IMAP protocols


Microsoft Exchangeno, but there could be installed filters that do change the code
IBM Domino

yes, removes unsupported HTML elements to Lotus Notes