Microsoft's email service, Outlook.com, now supports the IMAP protocol. While Windows Phone devices will continue to use the Exchanage ActiveSync protocol when communicating with Outlook.com, the addition of IMAP support makes it easier to use a wider range of apps and devices with the email service (e.g. Mac Mail and Thunderbird).

Microsoft has also implemented OAuth (authentication) support, which together with the new IMAP functionality, makes it much easier for third party services to integrates with Outlook.com. For example, such services can connect to your inbox, scan it, and carry out actions on your behalf (e.g. look for particular types of email and carry out an action).

Microsoft has implemented Outlook.com IMAP support as IMAP version 4 revision 1. Authorisation is done via OAuth 2.0. More technical details are available in this blog post.

As explained by the Outlook.com blog support for IMAP and OAuth support makes the service more flexible:

While we believe that EAS is the most robust protocol for connecting to your email, with syncing in near real time, and superior battery and network efficiency, there are still some devices and apps that haven't made the upgrade to EAS. As an older protocol, IMAP is widely supported on feature phones and other email clients such as those on a Mac. We heard your feedback loud and clear that this was important.

In addition to offering more complete device connectivity, IMAP (along with OAuth) gives developers opportunities to build third-party clients and services that offer value-added scenarios on top of your Outlook.com email. We are excited to launch the first set of services today that integrate with Outlook.com, and look forward to sharing many more in the future.

As part of today's announcement Microsoft is highlighting a number of partners that are using IMAP and OAuth to provide these "value added scenarios":

• TripIt - automatically creates mobile travel itinerararies based on email travel conformations (e.g. emails from airlines, hotels and car rental agencies).
    
• Sift -  uses existing shopping content in your inbox to help you find favourite stores and products.
    
• Slice - keeps track of everything you buy online, including package tracking.
    
• Unroll.me - provides a way to elimiate inbox clutter by helping you unsubscribe from unnecessary email subscriptions and bundling the ones you do want into a single daily email.
    
• OtherInbox - offers a range of tools to keep your inbox clean and streamlined. 
    
• and more
  

These services have the potential to improve your email experience if you are using an Outlook.com account on your Windows Phone device. TripIt, for example, greatly benefits from automatic email collection, because it is no longer necessary to forward travel emails to plans@tripit.com. That means travel plans appear automatically in the Tripit service, including in the Tripit Windows Phone app, without any direction action from the user.