List of email clients that Acorn is compatible with

Acorn has been (and is regularly) tested to render well in all major email clients.

We use both Email on Acid and Litmus to test. The following table shows all major email clients that Acorn supports and is compatible with:

Email Client or Operating SystemCompatible


Gmail Android1
Outlook Android

iOS (10+)



Apple Mail
Outlook 2011
Outlook 2016

Outlook (Windows)

Outlook 2003
Outlook 2007
Outlook 2010
Outlook 2011
Outlook 2013
Outlook 2016
Windows 10 Mail

Lotus Notes

Lotus Notes 8
Lotus Notes 8.5



Common Web Clients

Google Apps
Office 365
Yahoo! Mail

1 Gmail app used with a non-Google account (a.k.a. GANGA) does not currently support media queries, so it will render the desktop version. It also doesn't support background images.

Other notes:

  • Outlook does not support rounded or pill buttons, it shows 90° corners
  • For Web Clients, we officially support IE9+, Edge, Chrome, Firefox, and Safari (Mac)
  • Web fonts are supported only in Apple Mail, iOS Mail, native Android app (not Gmail), and Thunderbird
  • While we don't officially support them, we have seen Acorn rendering well in the vast majority of international email clients

Responsive, not hybrid

Acorn is a responsive email framework, meaning it relies on CSS @media queries for proper rendering on mobile devices. This means that email clients which do not support embedded CSS or media queries will show the desktop layout.

While hybrid coding does currently hold an advantage in this case, we have decided not to use it for the following reasons:

  1. Hybrid requires the use of 'ghost tables' - HTML table structures wrapped inside Outlook-specific HTML comments. They are needed with hybrid, because Outlook does not support the max-width CSS property. However, this adds extra weight to the HTML size and, being basically a comment, it's very hard to manipulate automatically (i.e. drag'n'drop builders, CSS inlining).
  2. Starting with Gmail's support for media queries in email back in 2016, we can clearly see the trend is to go towards supporting responsive, not away from it. It'll probably take a bit of time, but once Gmail will support media queries in the Gmail app for non-Google accounts too, there will be no reasonable justification to use hybrid coding.