In 2001 Microsoft introduced, among many other things, an invaluable productivity improvement to its Office suite (Microsoft Office 2002 at the time), that would raise the industry standard for professionals involved with a job that requires frequent email correspondence with a large client base for many years to come. Microsoft named its new feature “Mail Merge” – a welcome addition to the Microsoft Word application, which would allow a user to take an entirely different approach to communicating across a broad client base.
For many years Microsoft Outlook was the most popular email client in the world. According the latest research, Microsoft Exchange Server accounts for more than half of business mailboxes in 2014; that is, 500m in absolute figures. Many of these users are using Microsoft Outlook, where Outlook Web Access still plays a companion role.
The installation base of Microsoft Office is about 1 billion. This figure can be found in many articles. On July 7, 2014 Microsoft reported that over 1.1 billion people use Microsoft Office. So the estimated base of Microsoft Outlook users in 2014 is between 500m and 600m.
Some interesting numbers can be found in the research of the Radicati Group. This company specializes in researching e-mail, security, instant messaging and social networking with a focus on enterprise market.
In the study entitled “Microsoft Exchange Server and Outlook Market Analysis, 2010-2014”, we see that on-premises Exchange in 2010 has 76% of mailboxes as opposed to 15% being hosted and 9% from managed Exchange.