Hi Wolf-Networks,
Based on my experience, we can set permission for one user to view all other user’s calendars via Powershell script. After setting, we need to open the calendar manually in Outlook. So, your requirement may not be achieved. Given the situation, could you accept the following workaround(Set permission for one user)?
1. Connect to Exchange Online through PowerShell as administrator.
You can refer to this link:help.outlook.com/.../cc952755.aspx
2. Prepare a text file, save the following content in 4 lines.
foreach($user in (Get-Mailbox -RecipientTypeDetails UserMailbox)) {
$cal = $user.alias+":\Calendar"
Add-MailboxFolderPermission -Identity $cal -User your@domain.com -AccessRights reviewer
}
3. Save the text file to d:\cal.ps1 file, then run d:\cal.ps1 in PowerShell.
Please note you may need to run the Set-ExecutionPolicy Unrestricted to run the local script and use your email address instead of your@domain.com.
4. Create a SG and add all users into it. And then open calendar of SG in Outlook.
Thanks,
Johnny Zhang