"In a world where more than half of email messages are first read on a mobile device, it's essential to give people fantastic email experiences wherever they go," said Microsoft vice president Rajesh Jha in a blog post.
"The Acompli team is passionate about this quest. Their app provides innovative ways to focus on what's important in your inbox, to schedule meetings, and work with attachments and files."
Acompli's Javier Soltero said on his blog that the app "will become part of Microsoft's ambitious effort to reimagine productivity for the mobile era."
He noted that "18 months ago we started building a team and a product around the idea that we could make mobile email better. Today that journey continues as part of a larger organization with the technology, talent, and market reach that will help us take the vision of Acompli to hundreds of millions of mobile users across the world."