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Guide to CSS support in email clients

Full report on all 24 clients

Designing an HTML email that renders consistently across the major email clients can be very time consuming. Support for even simple CSS varies considerably between clients, and even different versions of the same client.

We’ve put together this guide to save you the time and frustration of figuring it out for yourself. With 23 different email clients tested, we cover all the popular applications across desktop, web and mobile email.

As the number of email clients continues to grow, we’ve decided to simplify the web-based version of the guide to focus on the 10 most popular email clients on the market. For the complete report on all 24 email clients across the desktop, web and mobile email world, download the complete guide in PDF format.

Style Element Outlook
2000/03		 Live
Hotmail		 Yahoo!
Mail		 Yahoo!
Classic		 Outlook
2007/10		 Apple
Mail		 Apple
iPhone		 Google
Gmail		 Lotus
Notes 6/7		 Lotus
Notes 8.5		 AOL
Desk 10
<style> in <head> Yes Yes Yes Yes Yes Yes Yes No No Yes Yes
<style> in <body> Yes Yes Yes Yes Yes Yes Yes No No Yes Yes
Link Element Outlook
2000/03		 Live
Hotmail		 Yahoo!
Mail		 Yahoo!
Classic		 Outlook
2007/10		 Apple
Mail		 Apple
iPhone		 Google
Gmail		 Lotus
Notes 6/7		 Lotus
Notes 8.5		 AOL
Desk 10
<link> in <head> Yes Yes Yes Yes Yes Yes Yes No Yes Yes Yes
<link> in <body> Yes Yes Yes Yes Yes Yes Yes No No Yes Yes
Selectors Outlook
2000/03		 Live
Hotmail		 Yahoo!
Mail		 Yahoo!
Classic		 Outlook
2007/10		 Apple
Mail		 Apple
iPhone		 Google
Gmail		 Lotus
Notes 6/7		 Lotus
Notes 8.5		 AOL
Desk 10
e Yes Yes Yes Yes Yes Yes Yes No No Yes Yes
* Yes Yes Yes No No Yes Yes No No Yes Yes
e.className Yes Yes Yes Yes Yes Yes Yes No No Yes Yes
e#id Yes No Yes Yes Yes Yes Yes No No Yes Yes
e:link Yes Yes Yes Yes Yes Yes Yes No No Yes Yes
e:active, e:hover Yes Yes Yes Yes No Yes Yes No No Yes Yes
e:first-line Yes No No Yes No Yes Yes No No Yes Yes
e:first-letter Yes No No Yes No Yes Yes No No Yes Yes
e > f No No Yes Yes No Yes No No No No No
e:focus No No Yes Yes No Yes Yes No No No No
e+f No No No No No Yes Yes No No No No
e[foo] No No Yes Yes No Yes Yes No No No No
Text & Fonts Outlook
2000/03		 Live
Hotmail		 Yahoo!
Mail		 Yahoo!
Classic		 Outlook
2007/10		 Apple
Mail		 Apple
iPhone		 Google
Gmail		 Lotus
Notes 6/7		 Lotus
Notes 8.5		 AOL
Desk 10
direction Yes Yes Yes Yes No Yes Yes No No Yes Yes
font Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
font-family Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
font-style Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
font-variant Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
font-size Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
font-weight Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
letter-spacing Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
line-height Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
text-align Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
text-decoration Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
text-indent Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
text-overflow CSS3 Partial or buggy support Partial or buggy support No No No Partial or buggy support Partial or buggy support Partial or buggy support No Partial or buggy support Partial or buggy support
text-shadow CSS3 No Partial or buggy support Partial or buggy support Partial or buggy support No Yes Yes Partial or buggy support No No No
text-transform Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
white-space No Yes Yes Yes Yes Yes Yes Yes No No No
word-spacing Yes Yes Yes Yes No Yes Yes Yes No Yes Yes
word-wrap CSS3 Partial or buggy support No Yes Yes No Yes Partial or buggy support No No Partial or buggy support Partial or buggy support
vertical-align Yes Yes Yes Yes No Yes Yes Yes No Yes Yes
Color & Background Outlook
2000/03		 Live
Hotmail		 Yahoo!
Mail		 Yahoo!
Classic		 Outlook
2007/10		 Apple
Mail		 Apple
iPhone		 Google
Gmail		 Lotus
Notes 6/7		 Lotus
Notes 8.5		 AOL
Desk 10
color Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
background Yes No Yes Yes Partial or buggy support Yes Yes Partial or buggy support No No Yes
-moz-background CSS3 No No No No No No No No No No No
-webkit-background CSS3 No No No No No Yes Yes No No No No
background-color Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
background-image Yes No Yes Yes No Yes Yes No No No Yes
background-position Yes No Yes Yes No Yes Yes No No No Yes
background-repeat Yes No Yes Yes No Yes Yes No No No Yes
-khtml-background-size CSS3 No No No No No Yes Yes No No No No
-moz-background-size CSS3 No No No No No No No No No No No
-o-background-size CSS3 No No No No No No No No No No No
-webkit-background-size CSS3 No No No No No Yes Yes No No No No
HSL Colors CSS3 Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
HSLA Colors CSS3 No No No No No Yes Yes No No No No
Opacity CSS3 No No No No No Yes Yes No No No No
RGBA Colors CSS3 No No No No No Yes Yes No No No No
Box Model Outlook
2000/03		 Live
Hotmail		 Yahoo!
Mail		 Yahoo!
Classic		 Outlook
2007/10		 Apple
Mail		 Apple
iPhone		 Google
Gmail		 Lotus
Notes 6/7		 Lotus
Notes 8.5		 AOL
Desk 10
border Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
-moz-border-color CSS3 No No No No No No No No No No No
-moz-border-image CSS3 No No No No No No No No No No No
-moz-border-radius CSS3 No No No No No No No No No No No
-webkit-border-radius CSS3 No No No No No Yes Yes No No No No
-moz-box-shadow CSS3 No No No No No No No No No No No
-moz-box-sizing CSS3 No No Yes No No No No No No Yes Yes
height Yes Yes Yes Yes No Yes Yes Yes No Yes Yes
margin Yes No Yes Yes Yes Yes Yes Yes No Yes Yes
padding Yes Yes Yes Yes Partial or buggy support Yes Yes Yes No Yes Yes
width Yes Yes Yes Yes No Yes Yes Yes No Yes Yes
Positioning & Display Outlook
2000/03		 Live
Hotmail		 Yahoo!
Mail		 Yahoo!
Classic		 Outlook
2007/10		 Apple
Mail		 Apple
iPhone		 Google
Gmail		 Lotus
Notes 6/7		 Lotus
Notes 8.5		 AOL
Desk 10
bottom Yes No No No No Yes Yes No No Yes Yes
clear Yes Yes Yes Yes No Yes Yes Yes No Yes Yes
clip Yes No No No No Yes Yes No No No Yes
cursor Yes Yes Yes Yes No Yes No No No Yes Yes
display Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes
float Yes Yes Yes Yes No Yes Yes Yes No Yes Yes
left Yes No No No No Yes Yes No No Yes Yes
opacity No No No No No Yes Yes No No No Yes
outline CSS3 No No Partial or buggy support Partial or buggy support No Yes Yes Partial or buggy support No No No
overflow Yes Yes Yes Yes No Yes No Yes No No Yes
position Yes No No No No Yes Yes No No Yes Yes
resize CSS3 No Yes Yes Yes No Yes No No No Yes Yes
right Yes No No No No Yes Yes No No Yes Yes
top Yes No No No No Yes Yes No No Yes Yes
visibility Yes Yes Yes Yes No Yes Yes No No No Yes
z-index Yes No No No Yes Yes Yes No No Yes Yes
Lists Outlook
2000/03		 Live
Hotmail		 Yahoo!
Mail		 Yahoo!
Classic		 Outlook
2007/10		 Apple
Mail		 Apple
iPhone		 Google
Gmail		 Lotus
Notes 6/7		 Lotus
Notes 8.5		 AOL
Desk 10
list-style-image Yes No Yes Yes No Yes Yes No No No Yes
list-style-position Yes Yes Yes Yes No Yes Yes Yes No No Yes
list-style-type Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes
Tables Outlook
2000/03		 Live
Hotmail		 Yahoo!
Mail		 Yahoo!
Classic		 Outlook
2007/10		 Apple
Mail		 Apple
iPhone		 Google
Gmail		 Lotus
Notes 6/7		 Lotus
Notes 8.5		 AOL
Desk 10
border-collapse Yes Yes Yes No Yes Yes Yes Yes Yes Yes Yes
border-spacing No No Yes Yes No Yes Yes Yes No No No
caption-side No Yes No No No No No Yes No No No
empty-cells No Yes Yes Yes No Yes Yes Yes No No No
table-layout Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes
Total Market Share 28% 16% 14% 9% 8% 7% 6% 1% 1%

Version History

22 April 2010

Updated the guide with the results of our CSS3 email client tests. 21 new properties were added, with varying levels of support observed across the popular email clients. Notably, Webkit clients were big winners, including Apple Mail, iPhone Mail and soon, the iPad. At this stage, CSS3 is recommended for decorative purposes in email (such as adding text-shadow), due to poor support for layout and box-model properties.

Discuss this on our blog.

27 August 2009

Added test results for the just launched MySpace Mail.

Discuss this on our blog.

6 August 2009

A complete rewrite of the guide that included 7 new mobile email clients and a focus on the most popular email clients. The web-based version of the guide now features the 10 most popular email clients, while the PDF guide includes all 23 email clients tested.

Discuss this on our blog.

26 August 2008

Replaced .Mac results with MobileMe.

Discuss this on our blog.

11 June 2008

We increased the number of clients we tested, 21 in total now. Gmail and Outlook 2007 continue to be our primary focus since CSS support continues to be limited.

Positive signs from Microsoft though, Entourage 2008 was released with significantly better CSS support.

Discuss this on the blog

19 April 2007

Outlook 2007 was released with less CSS support than Outlook 2003. A major step back for HTML email design.

New Yahoo! mail was released with better support for CSS, a positive sign to say the least! Windows Live Mail replaced Hotmail and nixed some CSS support in the process.

Read the report

30 March 2006

This was our original test. We added Windows Live Mail for the first time and ran through tests on Outlook 2003, AOL 9, Lotus Notes and Eudora.

Read the report