The tech giant has tweaked its email service to offer a more refined inbox, featuring "Clutter", which can be trained to organize messages and place those most likely to be ignored in a separate folder.

Other new developments include search suggestions and refiners, link previews and pins and flags, as well as the addition of 13 new graphic design themes.

This update, which is part of a wider overhaul of the Office 365-based infrastructure, is currently available to a small group of users in Preview. The new-look result will be made available to a broader audience through an opt-in program over the coming weeks.

Microsoft has also released the preview for Word, Excel and PowerPoint apps on Android phones.  According to the company, the Office for Android phone apps are modern, optimized for touch and designed for work on the go.

For Microsoft, the world's biggest software company, there's a lot at stake this summer as it rolls out Windows 10, the first operating system designed to run on PCs, tablets and phones.