# Script will connect to ExchangeOnline, gather all user inbox rules across the tenant and export to a CSV file locally. 
# Internal forwarding will appear as "Display Name" and include MailOwnerId in rule
# External forwarding will appear as "email@domain.com" [SMTP:email@domain.com]

# Create export path
$exportPath = "C:\temp\exports\UserMailboxRulesExport.csv"

# Prepare file (optional: overwrite each time script runs)
if (Test-Path $exportPath) { Remove-Item $exportPath }

# Get all mailboxes
$users = Get-Mailbox -ResultSize Unlimited

foreach ($user in $users) {
    $rules = Get-InboxRule -Mailbox $user.UserPrincipalName | Select-Object `
        @{Name='DisplayName'; Expression={$user.DisplayName}},
        @{Name='EmailAddress'; Expression={$user.PrimarySmtpAddress}},
        MailboxOwnerID,
        Name,
        Description,
        Enabled,
        RedirectTo,
        MoveToFolder,
        ForwardTo

    # Export rules if any exist
    if ($rules) {
        $rules | Export-Csv $exportPath -NoTypeInformation -Append
    }
}