Each time a subscriber opens an email sent with Campaign Monitor, we keep track of which email client they're using. Since 2009, we've measured email client popularity across many billions of emails and occasionally collate that data to show interesting trends in email client usage.
Earlier this year, our friends at Return Path predicted that mobile was to surpass web and desktop client usage by July, 2012. We found that this event happened as early as February, when mobile overtook webmail client usage. In April, desktop clients lost their top spot - and mobile has shown no signs of slowing down since. In the following graph, you can see how mobile market share has increased since we last updated our report in May, 2011, while desktop and web client market share has continued its shallow decline.
— Desktop
— Web
— Mobile
Below is the email client market share as of September 2012. These numbers are not exclusive, some people use more than one email client during the month - which registers each client used.
| • 35.6% iOS Devices | • 20.14% Outlook | • 13.57% Hotmail |
| • 11% Apple Mail | • 9.85% Yahoo! Mail | • 8.43% Gmail |
| • 4.74% Android | • 2.34% Windows Live Desktop | • 1.03% Thunderbird |
| • 0.79% AOL Mail |
| Email Client | Popularity |
| iOS Devices | 35.60% |
| iPhone | 25.05% |
| iPad | 9.74% |
| iPod Touch | 0.81% |
| Microsoft Outlook | 20.14% |
| Outlook 2000, 2003, Express | 7.68% |
| Outlook 2007 | 6.51% |
| Outlook 2010 | 5.96% |
| Hotmail | 13.57% |
| Apple Mail | 11% |
| Apple Mail 5 | 4.31% |
| Apple Mail 4 | 3.75% |
| Apple Mail 6 | 1.70% |
| Apple Mail 3 | 1.04% |
| Apple Mail 2 | 0.20% |
| Yahoo! Mail | 9.85% |
| Gmail | 8.43% |
| Android | 4.74% |
| Windows Live Desktop | 2.34% |
| Thunderbird | 1.03% |
| AOL | 0.91% |
| AOL Mail | 0.79% |
| AOL Desktop 9.1 | 0.12% |
| Sparrow | 0.19% |
| Windows Phone 7 | 0.14% |
| Lotus Notes 6 & 7 | 0.07% |
| Blackberry | 0.05% |
| Excite | 0.02% |
| Palm WebOS | 0.01% |
| Entourage 2004 | 0.01% |
| Unable to detect email client | 10.25% |
The movers and shakers highlights those email clients whose market share is growing or shrinking the fastest. This is done by comparing the average usage between 2011 and 2012.
The email client a person is using can only be detected if images are displayed. This can give an inflated weighting to email clients that display images by default, such as Outlook 2000 and the iPhone. It will also provide a lesser weighting to those that block images by default such as Gmail and Outlook 2007+. Those email clients that aren't capable of displaying images, such as older Blackberry models and other mobile devices cannot be included in this study.