Here at Donordigital, we obsess about "email clients," which are the various software tools that people use to read the email they receive. Our obsession derives from the fact that we have to test every email message campaign that we send out for our clients. Most of the time that goes smoothly.  Once in a while, an email message won't render correctly in, say, Microsoft Outlook 2004.

Email clients fall into three general categories: desktop software such as Microsoft Outlook or Apple Mail, webmail in the cloud such as Hotmail, Yahoo! Mail or Gmail, and then various email clients installed on mobile devices like iPhones or Blackberry.

Which got us wondering about the top email clients in use today.  Not surprisingly, various analysts have studied this issue.  We tracked down a 2010 report which shows the current state of the email client market, with data from almost 250 million email recipients.

Here's the Top 10 email clients in decending order of estimated market share:

  • Microsoft Outlook - 43%*
  • Hotmail - 17%
  • Yahoo! Mail - 13%
  • Gmail - 5%
  • Apple Mail - 4%
  • iPhone - 4%
  • Thunderbird - 2.4%
  • Windows Live Mail (Desktop) - 2%
  • AOL Mail - 1.2%
  • Lotus Notes - 0.4%
  • Others - 8%

* Outlook 2003 and earlier - 34%

* Outlook 2007 - 9%

Read about this report

Michael Stein has been a writer and digital strategist for progressive social causes for over two decades. He is the author of three books and numerous articles chronicling the rise of digital marketing, mobile, and online fundraising. He works as a consultant and coach to nonprofits, foundations, and educators, with a focus on marketing and fundraising in a multichannel and multiscreen world. Find Michael on Twitter at @mstein63.