As of May 2018: Microsoft Office 365 mail, OneDrive, SharePoint, Project and OneNote documents reside in data centres in Canada and are encrypted both in transit and at rest. Access to other applications (Skype, Teams, etc.) or to the Azure Directory may cross international boundaries.
For the most up-to-date information, visit the Microsoft Data Map. The University of Windsor Geo location is set to Canada.
For detailed information, consult the Microsoft Agreement, and look under the heading "Location of Customer Data at Rest".