Here's how it works for company administrators.
Company admins need to enable the integration manually:
With integration enabled, any files previewed or edited through the web client are transferred to an Office 365 cloud outside the RushFiles environment. Files are returned to their location and encryption state once editing ends.
If the integration is left disabled, the web client file previewer will be used, and files won't leave the RushFiles environment.
Here's how it works for end-users
End-users may preview and edit any Office documents. Upon clicking an office file in the web client, a new tab opens in the browser and displays a file preview:
Clicking the blue "Edit in Browser" button in the upper right corner transfers the users to Office Online where the file is then edited:
Note for old office formats: If a user edits .doc files, Office Online will transfer the document with the newer .docx extension and will not change the original .doc file. This applies to all old Office formats.
File size restrictions
There are certain limitations to Microsoft Office 365 online: