From: Stephen Williamson
Sent: Wednesday, August 06, 2014 2:04 PM
Updated: May 2019
Subject: What program do people, in general, use, when they read emails

Most Popular Email Applications

Click here for a recent list on the most popular email domains (by number of live emails).

The following stats on the most popular email apps in April 2019 is from, using their image display tracking software.

Opened via Apple Mail (or compatible app): Total 45% (Down 2% on May 2014)

Yes, Apple rules. Their hardware though has always been more "cutting edge", especially with Steve Jobs as the CEO, ever since 1978-1979 when the Apple II was the "coolest thing around", according to Bill Gates.

For new users:- Note that whenever you hit Apple Mail's Reply button, due to their limited memory iPhones and iPads remove embedded images (that includes pictures embedded in email signatures) from email correspondence replacing the images with text fields e.g. <image001.jpg>, <image002.jpg>.

Opened via Google Android (on Smartphones and Tablets) and Microsoft Windows (on Desktops): Total 51% (Up 9% on May 2014)

  1. Google Gmail 28% (Up 15% on May 2014)
    *Estimate 21% opened via mobile 7% via desktop
    *According to Google in 2015 in the article "Gmail with 900 million users - Google's I/O developers conference (May 2015) - TechCrunch" 75 percent of Gmail users access their accounts on mobile devices. Note, independent verification of this 75-25 split is unavailable as Gmail access doesn't differentiate between mobiles and desktops
  2. Microsoft Outlook (via desktop) 9% (Down 4% on May 2014)
  3. Yahoo! Mail (via desktop & mobile) 6% (Up 1% on May 2014)
  4. Google Android (via mobile) 3% (Down 2% on May 2014)
  5. Microsoft (via desktop & mobile, previously Hotmail) 2% (Down 3% on May 2014)
  6. Samsung Galaxy Email App (via mobile) 2% (New since May 2014)
  7. Mozilla Thunderbird (via desktop & mobile) 1% (Same as May 2014)

Opened via another mobile/webmail/desktop program: Total 4% (Down 7% on May 2014)


Note that Outlook and retain their presence, though as an overall percentage Microsoft has lost considerable ground to Gmail and Apple. Still, I think many conservative offices (private and government) appreciate the "longevity" in the software. Electronic documents from the 1980's and 1990's, created with Wordstar, WordPerfect and Word, Lotus 1-2-3, Quattro Pro and dBASE can still be converted and read on WindowsXP and Windows7,8,10 machines today, years after the paper records have disappeared. Can be useful if "enemies" are taking you to court.


Now, with regard to the "rules", the protocols involved, click here for short definitions of the differences between WebMail, POP3 and IMAP.

More technically, and to summarize:

  1. Between networks, email is sent using SMTP-Simple Mail Transport Protocol (created in 1982). The rules are covered in RFC 821.
  2. POP-Post Office Protocol (created in 1984), where the emails are downloaded to your local desktop or mobile and then normally deleted from the server, is a retrieval protocol only, with the rules covered in RFC 1939.
  3. IMAP-Internet Message Access Protocol (created in 1986) where the emails are synchronized permanently on a central server, is another retrieval protocol, covered in RFC 3501.
  4. MAPI-Messaging Application Programming Interface (developed by Microsoft since about 1992), is a way for desktops, mobile phones and tablets to be able to communicate with Microsoft Exchange servers using IMAP style syncing of emails, contacts and calendars. Click here for further details.
  5. WEBMAIL (created about 1993) All WebMail providers give you a web page interface to your mailbox, and then apply and use SMTP and IMAP protocols, as specified in these RFC documents.
    So when you send an email (including any attachments) via a WebMail provider, you are actually submitting a form (HTTP), through your ISP, up to the WebMail provider's web server. Noting too, that if there's a long delay in any attachment arriving, the attachment may well be dropped. Then the WebMail provider hands the email over to its mail server (SMTP).
    Trust that's clearer.
    Click here for further history of Webmail.

** End of report