I've just finished writing our first email client market share report. It's the biggest study of email client usage ever conducted, using a sample of almost three million email recipients! I expect you'll find it very useful when deciding which email clients to test your designs with.
We're making it freely available under a Creative Commons license so you can adapt the information to use in your own reports.
It's exciting for us because it's the first time we've released any of the data that's been collected through Fingerprint. It shows the top 10 email clients in use for both consumer and business mailing lists.
Read the full report over on the Fingerprint site.

Comments
Makes for a very interesting read, I was especially surprised to see that Outlook is not the most popular business email client, what are you thoughts on this? :)
Posted by Nathan Pitman on September 13, 2008 7:47 AM
Thanks Nathan, glad you found it useful.
That's an excellent question regarding Outlook. However, if you combine both the Outlook stats, it reaches 35%, i.e. more share than Hotmail.
I thought it was important to break down the difference between 2003 and earlier, and 2007, because of the huge rendering differences.
I was still surprised to see Hotmail so high on the list, though.
Posted by Paul Farnell on September 13, 2008 12:10 PM
hi paul,
thanks for doing this study - very interesting.
i too was very surprised about hotmail. my most immediate thoughts are that perhaps people are viewing the mailing outside of work, and also that they may be using a non-work email address to subscribe to the mailing, even though it is a 'business' mailing.
could you tell me - what is the breakdown of geographic regions of participants? would you consider this to be a US-centric study?
thanks,
denise
Posted by denise cox on September 15, 2008 9:16 AM
Hi There,
Very interesting indeed.
Do you know what percentage of people use Outlook2002 specifically?
Thanks
Posted by Ben on September 19, 2008 2:59 AM
Denise: Glad you found it useful! Unfortunately, we don't have accurate per-recipient data on location. However, we do know that the majority of the mailing lists analysed are based in the US and the UK so it's likely their recipients are also.
Ben: Unfortunately we're not yet able to differentiate between Outlook 2003 and Outlook 2002. Sorry about that.
Posted by Paul Farnell on September 19, 2008 10:13 AM
Hi Paul,
Really interesting report - thanks for making it available for all to see.
I'm interested to know why Outlook Express isn't on this though as its shipped with most copies of XP and I thought it was popular...?
Or is it contained in your "Outlook 200x" results perhaps?
Keep up the great work!
Laura
Posted by Laura James on October 9, 2008 9:51 PM
Laura: Really glad you found it useful! You're correct that Outlook Express users are counted amongst the other Outlook statistics.
Posted by Paul Farnell on October 10, 2008 10:22 AM
Good job Paul!
Like the other readers, the thought that came to my mind was ... " hmmmm... very interesting! "
Seems that the reasons for so much Hotmail and web based mail... gmail, yahoo and others is because they are free, and because the consumer market that has moved into the internet realm. Consumers in general know just enough about computers to get on the internet to shop. (Meaning the majority of email users are not real computer savvy.)
Could there be a possibility that this study shows that Hotmail, and Outlook are the loosest in letting your survey come through, and the smaller market shares more secure in blocking it, as though it was spam?
Maybe in a few years Google (gmail) will take over the world instead of Microsoft (hotmail).
The reason people would want to look for such a report as this, is to make an intelligent decision on what to do about their email client tools. For security reasons I would stick to the smaller market shares.
I am glad you did this study. Thank you.
Posted by Jer Bar on October 22, 2008 3:18 PM
http://friendfeed.com/e/450025cb-26ac-462f-abae-7355ff0aad17/Email-Client-Statistics-Fingerprint/
your turn! ; )
Posted by Erhan on November 3, 2008 8:53 AM
Erhan: Thanks for the link. I answered some of the specific questions in your comments.
Posted by Paul Farnell on November 4, 2008 7:37 PM
Thanks for publishing these stats, very interesting stuff. I'm looking forward to using the tool to conduct some research on our own lists.
Posted by Nick Whiteacre on November 27, 2008 4:17 AM
Incidentally, how often is the survey blocked? Do you have any figures for how many times the survey failed to return information because the image was blocked?
Posted by David on December 5, 2008 5:00 PM
Paul,
Good study. Are you aware of how this might translate into absolute numbers of users?
Would this be just the US?
Regards,
Gary
Posted by Gary Peyrot on April 15, 2009 4:22 PM
FWIW - I believe part of the HOTMAIL adoption rates is perhaps due to all the versions of Outlook can import Hotmail INTO Outlook. So it acts like a low-level exchange server...
So you can get your Hotmail email in Outlook, or log onto any web computer and view your email there.
Just an idea.
What was a big surprise was that GMail wasn't as ubiquitous as it seemed. Good news there. Shows perhaps Google isn't as cool as we are led to believe.
Posted by percy chow on May 6, 2009 10:21 PM
Paul, these are interesting numbers - however I believe that great differences exist across countries? Yahoo is not very popular in Denmark, for example. Could be interesting to see these numbers broken down by country too.
And I'm a little curious: how do you tell the difference between an Outlook 2003 user running IE7 vs. one running IE6? How would the two show in the report?
As mentioned in your excellent screencast "Understanding desktop email clients" (http://litmusapp.com/resources/desktop-email-clients) both scenarios are possible.
Posted by Mikkel Steen Andersen on May 26, 2009 10:10 AM
Having been very surprised by these results, something then sprung to mind: if the data comes from mailing list subscriptions, it's likely to be very biased.
I use Outlook and Thunderbird for *real* e-mail, but when subscribing to a mailing list, I normally use a "throw-away" address such as Hotmail, Gmail, Mailinator and so on.
A quick straw poll around the office suggested this was common behaviour, so I suspect this leads to a significant skew in the data.
Posted by Rob C on December 17, 2009 2:25 PM
Interesting point, Rob. You may be right. I'd love to figure out a way to test that hypothesis.
Personally, I think that scenario is more likely within a technical audience. Amongst the general population (I'm thinking of my friends and family members here, rather than work colleagues), I wouldn't expect it to be anywhere near as common.
Posted by Paul Farnell on December 21, 2009 3:02 AM
Useful information but now a little old.
Given changes in smart phone use and updated report would be most interesting, to highlight changes.
Posted by Tim Watson on January 11, 2010 9:32 AM
Tim - Agreed. We'll be publishing an full update to this report within the next month or so.
Posted by Paul Farnell on January 11, 2010 2:45 PM