Microsoft is planning to replace the technology and interface of Outlook.com with Office 365. Sources familiar with Microsoft’s plans tell The Verge that the company is migrating all Outlook.com users over to Office 365 this year. Microsoft’s Office 365 service includes Outlook Web Access, and we’re told Outlook.com will start to align with this user interface and feature set. The Outlook.com name will remain for consumers, and the Office 365 technology will help power it separately as a free email service without the subscription benefits of Office 365.

The primary reason for the migration is to ensure Microsoft’s Outlook, Exchange, and Office 365 platforms are aligned, and that means adding the consumer Outlook.com service into this mix to keep everything consistent. In an interview with The Verge last week, Microsoft’s general manager of Office Apps, Rob Lefferts, speculated there could be some UI changes as part of the swap. "I expect there will be some visual enhancements," said Lefferts. "We debated a couple of ways we could have gone about it, but given the other goals we have for Exchange, Outlook, and Outlook.com it seemed like the most straightforward way to do it."

How Outlook.com may look in future.

Microsoft hasn't updated Outlook.com with major changes for months now, and the company recently killed off Google and Facebook chat ahead of its migration plans. Any potential UI changes will likely involve Microsoft moving toward its Outlook Web App interface used on Office 365. It's largely similar to Outlook.com, so most Hotmail and Outlook.com users will already be familiar with any future changes. Microsoft's migration of Outlook.com will help the company provide add-ins across Outlook for desktop, mobile, and web thanks to a single codebase that developers can hook into.