Office 365 – Change default calendar to Reviewer

Problem:

Client wanted to change every user’s calendar to review only.

Solution:

1. Connect-ExchangeOnline -UserPrincipalName navin@contoso.com
2. $users = Get-Mailbox -Resultsize Unlimited
3. foreach ($user in $users) { Write-Host -ForegroundColor green Setting permission for $($user.alias)… Set-MailboxFolderPermission -Identity $($user.alias):\calendar -User Default -AccessRights Reviewer }

Please note that this has to be run every time as it changes the current list of users rather than modify the default behaviour.