From: Stephen Williamson
Sent: Wednesday, August 06, 2014 2:04 PM
Updated: 2023-2024
Subject: What program do people, in general, use, when they read emails

Most Popular Email Applications

Then and now: Login pages for AOL Dial-Up 2.0, left, released in 1994 and AOL Desktop 9.8.2 in 2017.
Made famous in 1999 comedy "You've Got Mail"

Click here for an attempt (very kludgy but somewhat successful) to log on to AOL over a dial-up network using Windows 10 in 2017.

Click here for the history of commercial email IBM, DEC, ITU, AOL, Microsoft, Yahoo, GMail

Click here for the AOL Timeline (1985 - 2015) now Verizon.

Click here for a June 2016 list of 100 of the most popular email networks (according to the number of live emails involved).
Just over 50% of emails that were sent used four domains: (Google) 17.7%, 17.3%, (Microsoft) 15.5%, then a big drop to 3.2% followed by further Microsoft and Yahoo email domains (country specific) around 1%.

Top Email Providers in 2024


In-house Software

Microsoft Exchange server software (also launched in 1996) currently oversees 300,000 separate mail servers worldwide e.g. etc that look after 350 million users, and 7 billion "mailboxes" - noting that word "mailbox" has a very broad meaning .

Mail Server software also runs on the IBM Lotus Domino Server (about 40,000 companies)

and Novell Groupwise servers, apparently a distant third.
Novell was sold to Attachmate in 2011, British firm Microfocus in 2014, and Canadian firm Opentext in 2023.

Note, Apple icloud (launched in 2011) provides file storage services to 850 million users (iphones, ipads, imacs etc) though no statistics of how many use as their email address are available. Apple's is free to all, but only up to 5gb, as opposed to 15gb on

As far as the use of the Apple Mail app is concerned, the following June 2023 user statistics comes from, using their image display tracking software.

  1. Opened via Apple Mail: Total 58.55% (Up 11.55% on May 2014)

    Note, since August 2021, Apple Mail clients rarely specify whether an iPhone, iPad, or Mac desktop/laptop is being used. Below are some stats from August 2021.

    Apple is still ahead of Google and Microsoft. Their hardware has historically been more "cutting edge", especially when Steve Jobs was the CEO, ever since 1978-1979 when the Apple II was the "coolest thing around", according to Bill Gates.

    One of the iPhone's early features was its "push email" support from Microsoft Exchange servers and Apple servers i.e., (now discontinued) and Click here for a discussion in 2018.

    For new users:- Noting too 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>.

  2. Opened via Gmail: Total 28.17% (Up 15.17% 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.

    Independent verification of this 75-25 split is unavailable as Gmail access doesn't differentiate between mobiles and desktops

  3. Microsoft Outlook (via desktop & mobile) 4.33% (Down 8.67% on May 2014)
  4. Yahoo! Mail (via desktop & mobile) 2.75% (Down 2.25% on May 2014)
  5. Google Android (via mobile) 1.56% (Down 3.44% on May 2014)
  6. Microsoft (via desktop & mobile, previously Hotmail) 0.64% (Down 4.36% on May 2014)
  7. Mozilla Thunderbird (via desktop) 0.25% (Down 0.75% on May 2014)
  8. Samsung Galaxy Email App (via mobile) 0.15% (Not Reported in May 2014)
  9. Windows Live Mail (via desktop) 0.05% (Not Reported in May 2014)
  10. QQ Mail (via desktop & mobile) 0.05% (Not Reported in May 2014)

Opened via another mobile/webmail/desktop program: Total 3½% (Down 7½% 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.

MAXIMUM STORAGE ROOM for Email folders (all sending and receiving history)

IMAP / WebMail in Australia
Optus Servers 500mb
TPG Servers 2gb
Telstra Servers 10gb (since 2016)

In the US
Gmail Servers (each account) 15gb (Microsoft) Servers (each account) 15gb
Yahoo Servers 1 terabyte (all accounts)
Apple iCloud Servers 5gb free, 50GB: $1.49 monthly AUD, 200GB: $4.49, 2TB: $14.99


SENDING an Email with large attachments (maximum size permitted)

Optus Servers 10mb
TPG Servers 20mb
Telstra Servers 25mb

In the US
Gmail Servers 25mb Servers (Microsoft) 34mb
Yahoo Servers 25mb
Apple iCloud Servers 20mb

Both Microsoft Outlook and Apple Mail baulk at sending emails greater than 20mb.
For large attachments, use Dropbox, Google Drive, or Microsoft's OneDrive.

** End of report