Classic Outlook COM automation fails when run via ServiceNow ACC agent / Local System

try {
    $olApp = New-Object -ComObject Outlook.Application
    $session = $olApp.GetNamespace("MAPI") 
    $syncs = $session.SyncObjects
    if ($syncs.Count -eq 0) {
        Write-Host "No Send/Receive groups found."
        return
    }

    for ($i = 1; $i -le $syncs.Count; $i++) {
        $syncObj = $syncs.Item($i)
        Write-Host "Syncing group: $($syncObj.Name)"
        $syncObj.Start()
    }
    Write-Host "Outlook Sync Successfull"

    [System.Runtime.InteropServices.Marshal]::ReleaseComObject($syncObj) | Out-Null
    [System.Runtime.InteropServices.Marshal]::ReleaseComObject($syncs) | Out-Null
    [System.Runtime.InteropServices.Marshal]::ReleaseComObject($session) | Out-Null
}
catch {
    Write-Host "Error: Exception occurred while syncing Outlook. $_"
}

What the script does:

Creates the Classic Outlook COM object, gets the MAPI NameSpace, enumerates SyncObjects (Send/Receive groups), and calls SyncObject.Start() to trigger a Send/Receive. (Refs: Outlook OOM GetNamespace("MAPI"), SyncObjects, SyncObject.Start).

Question

We use Classic Outlook for Windows (Microsoft 365 Apps). The above PowerShell/COM automation works perfectly when run under a normal, logged‑in user session. But when the same script runs via the ServiceNow ACC agent (Windows service) or under the Local System account, Classic Outlook fails to initialize the MAPI profile and no sync occurs.

We need Microsoft’s guidance on:

• Is there any supported way to programmatically trigger Classic Outlook Send/Receive from a non‑interactive platform such as ServiceNow ACC (service), Local System, or any unattended execution context?

Environment details:

• Classic Outlook for Windows (Microsoft 365 Apps)
• Windows 10/11
• PowerShell + COM/OOM as shown above
• Works in interactive user session
• Fails under ServiceNow ACC agent (service) and Local System

Goal: Programmatically trigger Classic Outlook’s Send/Receive in enterprise automation workflows, or validate the recommended Microsoft‑supported path to achieve the same result without relying on desktop OOM in a service context.

Apart from the classic Outlook issue — question for New Outlook (web‑based)

“For the New Outlook for Windows (web‑based), which does not support COM automation or VBA, what is the Microsoft‑supported way to programmatically perform mailbox actions equivalent to Send/Receive (e.g., send, create, process messages)—should we use Microsoft Graph and/or Office.js web add-ins, and can Microsoft confirm there is no client-side Send/Receive trigger in New Outlook since sync is service‑driven?”