Now office 365 customers have the option of integrating Office 365 and Cortona in Windows 10 for the end users.

By having this option enabled this will help users to be informed through cortona about their future meetings.
To use Cortana, people must be signed in to their windows 10 PC with their work account inorder to authorize Cortana to access Office 365 on their behalf.

Cortana can also access email and calendar data from users through various client apps running on Windows 10.

By default this is turned on in office 365 . To turn this off perform the following

Go to the Office 365 admin center.

Expand Service Settings, and select Cortana.

Click Cortana to toggle Cortana off.

IMP:

Currently the support for Cortona with Outlook is planned for future release. So inorder to use with office 365 we need to setup the Windows 10 Outlook Universal Mail and Calendar apps with Office 365.

Cortona will work only on devices running on Windows 10 and available only few languages as of now.

Thanks

Sathish Veerapandian