Set default calendar permissions for all users with PowerShell

The default calendar sharing permissions in Exchange Online are set as AvailabilityOnly. What if you want to change that? It’s possible to change default calendar permissions for the users one by one, but that will take time. Another way is to set default calendar permissions for all users with a PowerShell script. Let’s find out how.

Default calendar permissions

A lot of companies want the default calendar set as LimitedDetails instead of the default AvailablityOnly. That’s because you will see more information in the calendar item of your colleagues.

How it looks with permission AvailabilityOnly:

How it will look with permission LimitedDetails:

In the previous article, we looked at how to manage calendar permissions in Office 365 with PowerShell. Please have a read and get yourself familiar with the commands.

What if you want to set the default for all the users’ calendars? Will you run the Set-MailboxFolderPermission command for all the users one by one? That will take some time, and maybe you will forget a user. Let’s look at the next step about the PowerShell script that will do the work.

Prepare set default calendar permissions PowerShell script

Create two folders on the (C:) drive:

• Temp
• Scripts

Download Set-DefCalPermissions.ps1 script and place it in C:\scripts folder. The script will place the transcripts logs in the C:\temp folder.

Ensure the file is unblocked to prevent errors when running the script. Read more in the article Not digitally signed error when running PowerShell script.

Another option is to copy and paste the below code into Notepad. Give it the name Set-DefCalPermissions.ps1 and place it in the C:\scripts folder.

<#
    .SYNOPSIS
    Set-DefCalPermissions.ps1

    .DESCRIPTION
    Set default calendar permissions for all user mailboxes including exception for users.

    The script works for:
    -Exchange On-Premises (Run Exchange Management Shell)
    -Exchange Online (Connect to Exchange Online PowerShell)

    .LINK
    alitajran.com/set-default-calendar-permissions-for-all-users-powershell

    .NOTES
    Written by: ALI TAJRAN
    Website:    alitajran.com
    LinkedIn:   linkedin.com/in/alitajran

    .CHANGELOG
    V1.00, 02/28/2021 - Initial version
    V1.10, 03/29/2023 - Changed Exceptions to look for UserPrincipalName
#>

# Start transcript
Start-Transcript -Path "C:\temp\Set-DefCalPermissions.log" -Append

# Set scope to entire forest. Cmdlet only available for Exchange on-premises.
#Set-ADServerSettings -ViewEntireForest $true

# Get all user mailboxes
$Users = Get-Mailbox -ResultSize Unlimited -RecipientTypeDetails UserMailbox

# Users exception (add the UserPrincipalName)
$Exception = @("irene.springer@exoip.com", "richard.grant@exoip.com")

# Permissions
$Permission = "LimitedDetails"

# Calendar name languages
$FolderCalendars = @("Agenda", "Calendar", "Calendrier", "Kalender", "日历")

# Loop through each user
foreach ($User in $Users) {

    # Get calendar in every user mailbox
    $Calendars = (Get-MailboxFolderStatistics $User.UserPrincipalName -FolderScope Calendar)

    # Leave permissions if user is exception
    if ($Exception -Contains ($User.UserPrincipalName)) {
        Write-Host "$User is an exception, don't touch permissions" -ForegroundColor Red
    }
    else {

        # Loop through each user calendar
        foreach ($Calendar in $Calendars) {
            $CalendarName = $Calendar.Name

            # Check if calendar exist
            if ($FolderCalendars -Contains $CalendarName) {
                $Cal = "$($User.UserPrincipalName):\$CalendarName"
                $CurrentMailFolderPermission = Get-MailboxFolderPermission -Identity $Cal -User Default
                
                # Set calendar permission / Remove -WhatIf parameter after testing
                Set-MailboxFolderPermission -Identity $Cal -User Default -AccessRights $Permission -WarningAction:SilentlyContinue -WhatIf
                
                # Write output
                if ($CurrentMailFolderPermission.AccessRights -eq "$Permission") {
                    Write-Host $User.DisplayName already has the permission $CurrentMailFolderPermission.AccessRights -ForegroundColor Yellow
                }
                else {
                    Write-Host $User.DisplayName added permissions $Permission -ForegroundColor Green
                }
            }
        }
    }
}

Stop-Transcript

The PowerShell script will have some additions that will help you to meet some requirements for the organization:

• Exclude users that you don’t want the script to run against. Add them in line 35. If you don’t need this feature, comment out lines 35, 50, 51, 52, 53, and 77.

• Calendars are not always set in the English language. For example, in The Netherlands, it’s named Agenda. The script will check for the calendar names defined in line 41.

• Change permission that you want to set for all the users in line 38.

In the next step, you will run the script and see it in action.

Bulk set default calendar permissions PowerShell script

You must connect with the proper tools before you run the script:

• Exchange on-premises: Run Exchange Management Shell as administrator.

• Exchange Online (Microsoft 365/Office 365): Run PowerShell as administrator and connect to Exchange Online PowerShell.

Change the directory to the script path and run Set-DefCalPermissions.ps1 PowerShell script.

The script will go through all the mailboxes in Exchange Server/Exchange Online.

Note: The -WhatIf parameter is added in the script on line 65. If you run the script, nothing will happen in the environment. Instead, you get an output showing what will happen.

PS C:\> cd c:\scripts
PS C:\scripts>.\Set-DefCalPermissions.ps1
Transcript started, output file is C:\temp\Set-DefCalPermissions.log
What if: Setting mailbox folder permission "'LimitedDetails'" on "Zoë Roberts:\Calendar" for user "Default".
Zoë Roberts added permissions LimitedDetails
What if: Setting mailbox folder permission "'LimitedDetails'" on "Madeleine Fisher:\Agenda" for user "Default".
Madeleine Fisher added permissions LimitedDetails
Irene Springer is an exception, don't touch permissions
What if: Setting mailbox folder permission "'LimitedDetails'" on "Grace Rees:\Calendar" for user "Default".
Grace Rees added permissions LimitedDetails
What if: Setting mailbox folder permission "'LimitedDetails'" on "Kylie Davidson:\Calendar" for user "Default".
Kylie Davidson added permissions LimitedDetails
Richard Grant is an exception, don't touch permissions
What if: Setting mailbox folder permission "'LimitedDetails'" on "Dylan Piper:\Calendar" for user "Default".
Dylan Piper added permissions LimitedDetails
Transcript stopped, output file is C:\temp\Set-DefCalPermissions.log

Remove the -WhatIf parameter from the PowerShell script and rerun the script to set the default calendar sharing permissions for all users.

PS C:\scripts>.\Set-DefCalPermissions.ps1
Transcript started, output file is C:\temp\Set-DefCalPermissions.log
Zoë Roberts added permissions LimitedDetails
Madeleine Fisher added permissions LimitedDetails
Irene Springer is an exception, don't touch permissions
Grace Rees added permissions LimitedDetails
Kylie Davidson added permissions LimitedDetails
Richard Grant is an exception, don't touch permissions
Dylan Piper added permissions LimitedDetails
Transcript stopped, output file is C:\temp\Set-DefCalPermissions.log

Verify default calendar permissions

The output will show in the Windows PowerShell console. Not only that, it will show the output in a log because a transcript is added to the PS script.

Go to the C:\temp folder and open the Set-DefCalPermissions.log file.

I hope this helped you to change default calendar permissions in Exchange Online and Exchange Server on-premises.

Keep reading: Assign Microsoft 365 licenses with group-based licensing »

Conclusion

You learned how to set default calendar permissions for all users with the Set-DefCalPermissions.ps1 PowerShell script. When you need to change the default calendar permissions for many users, automate the process. It will save time, and you can always check the transcript logs with the changes.

Did you enjoy this article? You may also like How to enable external forwarding in Microsoft 365. Don’t forget to follow us and share this article.