Powershell for each scripts not sequential

Question

I have the following PowerShell for each statement that loops over a list of about 50 mailboxes and runs 2 scripts on each one. These 2 script take about a hour to complete. Because of the sequential nature of PowerShell this would take ~50 mailboxes * 1 hour = 50 hours.

Is it possible for PowerShell to run the script on each mailbox on the same time, in parallel?

Foreach($mailbox in $mailboxes){
    Write-Host "$(Get-TimeStamp) Start of adding contacts $mailbox"
        & $scriptPath -Mailbox  $mailbox.UserPrincipalName -ClientSecret $clientSecret -ClientID $clientID -TenantID $tenantID -CSVPath $csvPath
    Write-Host "$(Get-TimeStamp) Start of deduplicating contacts $mailbox"
        & $scriptPath2 -Mailbox  $mailbox.UserPrincipalName -ClientSecret $clientSecret -ClientID $clientID -TenantID $tenantID 
}

Answer 1

How about using the Start-Job?

$jobs = @()

foreach ($mailbox in $mailboxes) {
    $job1 = Start-Job -ScriptBlock {
        Write-Host "$(Get-TimeStamp) Start of adding contacts $mailbox"
        & $scriptPath -Mailbox  $mailbox.UserPrincipalName -ClientSecret $clientSecret -ClientID $clientID -TenantID $tenantID -CSVPath $csvPath
    }

    $job2 = Start-Job -ScriptBlock {
        Write-Host "$(Get-TimeStamp) Start of deduplicating contacts $mailbox"
        & $scriptPath2 -Mailbox  $mailbox.UserPrincipalName -ClientSecret $clientSecret -ClientID $clientID -TenantID $tenantID 
    }

    $jobs += $job1, $job2
}

# Wait for all jobs to finish and retrieve results (if any)
$jobs | Wait-Job
$jobResults = $jobs | Receive-Job

# Clean up jobs and display results if needed
$jobs | Remove-Job
$jobResults