If you use Outlook Web Access (aka Outlook on the Web) with Exchange Online, you can now get more insights for your meetings.
When you check your meeting in OWA, Outlook will find additional relevant information from emails from your mailbox and/or files saved in OneDrive (including shared ones) or SharePoint Online, helping you getting more insights for your meeting.
To get these details, just logon to your mailbox using Outlook on the Web (https://outlook.office365.com) and go to your calendar to check your meeting; you may have to scroll down the body of the meeting request to get the Meeting Insights
