Recently the Helpdesk have been getting cases about slow delivery times due to Office 365 ATP Safe Attachments. We have created a script to retrieve the data from Exchange Online, and then used Power BI to visualize it.
Per default the calendars of shared mailboxes in Office 364 have “FreeBusyTimeOnly” permissions applied.
You could create a new sharing policy and change the applied policy on those accounts.
I however chose to just change the sharing permissions on the shared calendar.
The GUI at Microsoft is great but sometimes we need to dig a bit deeper.
I ran into some issues with a Resource mailbox and had to do some troubleshooting in the Office 365 service.