What’s even more surprising is that Microsoft’s heart seems to be in the effort.

Over the last several months, Microsoft has been taking up more and more space on my own iPhone’s home screen. I’ve installed mobile versions of its Office apps as well as OneDrive, the company’s answer to Dropbox, Google Drive and other cloud storage services.

For the last couple of weeks, I have also relied heavily on Microsoft’s latest mobile creation, Outlook for the iPhone. (It’s available on Android, too; both versions are free for personal use.) Outlook is an email and calendar app that bears a resemblance to the PC version of the software, but mostly just in name. Instead of trying to jam all the features of the PC version into the app, Outlook is thoughtfully tailored for how people use email on smartphones.

The new Outlook is not Microsoft’s work, exactly. The app is mostly a rebranding of Acompli, an existing app made by a start-up that Microsoft acquired in December for $200 million. But there is no shame in using acquisitions to inject new talent and technology into a company. Facebook, Google and Amazon all employ a similar strategy.

The fact that Microsoft released the new Outlook in late January, when the ink was barely dry on its Acompli deal, is a clear sign of how quickly the company feels it needs to move in the mobile business. Last week, the company bought the maker of Sunrise, a popular mobile calendar app, suggesting that Microsoft has no plans to let up on its deal-making.

Until it released its new mail app, Microsoft offered OWA for iPhone and Android. The name stands for Outlook Web Access, and as the name suggests, the app was essentially a shortcut to a web page and lacked the performance and richness of a native mobile app.