PowerShell cmdlet for removing attachments from *.msg files

Remove-MsgAttachment.ps1

function Remove-MsgAttachment
{
    [CmdletBinding()]

    Param
    (
        [Parameter(ParameterSetName="Path", Position=0, Mandatory=$True)]
        [String]$Path,

        [Parameter(ParameterSetName="LiteralPath", Mandatory=$True)]
        [String]$LiteralPath,

        [Parameter(ParameterSetName="FileInfo", Mandatory=$True, ValueFromPipeline=$True)]
        [System.IO.FileInfo]$Item
    )

    Begin
    {
        # OlInspectorClose constants
        $olSave = 0
        $olDiscard = 1
        $olPromptForSave = 2

        # OlSaveAsType constants
        $olTXT = 0
        $olRTF = 1
        $olTemplate = 2
        $olMSG = 3
        $olDoc = 4

        # Load application
        Write-Verbose "Loading Microsoft Outlook..."
        $outlook = New-Object -ComObject Outlook.Application
    }

    Process
    {
        switch ($PSCmdlet.ParameterSetName)
        {
            "Path"        { $files = Get-ChildItem -Path $Path }
            "LiteralPath" { $files = Get-ChildItem -LiteralPath $LiteralPath }
            "FileInfo"    { $files = $Item }
        }

        $files | % {
            # Work out file names
            $msgFn = $_.FullName

            # Skip non-.msg files
            if ($msgFn -notlike "*.msg") {
                Write-Verbose "Skipping $_ (not an .msg file)..."
                return
            }

            # Open the msg file
            $msg = $outlook.Session.OpenSharedItem($msgFn)

            # Do not touch files without attachments
            if ($msg.Attachments.Count -eq 0) {
                Write-Verbose "Skipping $_ (has no attachments)..."
                $msg.Close($olDiscard)
                return
            }

            # Clone message
            $msgCopy = $msg.Copy()
            $msg.Close($olDiscard)

            # Remove attachments from message
            Write-Verbose "Removing attachments from $_..."
            while ($msgCopy.Attachments.Count -gt 0) {
                $msgCopy.Attachments.Remove(1)
            }

            # Save message
            $msgCopy.SaveAs($msgFn, $olMSG)
        }
    }

    End
    {
        Write-Verbose "Done."
    }
}

No worries. Any time. :)

If you unwrap everything in the .ps1 file so that it's not enclosed in a function, then I think you can run the script directly as you were doing it (without having to Import-Module first).

That is, if you change --

function Remove-MsgAttachment
{
    [CmdletBinding()]
    Param
    (
        # ...
    )

    # ...

    End
    {
        Write-Verbose "Done."
    }
}

to --

[CmdletBinding()]
Param
(
    # ...
)

# ...

End
{
    Write-Verbose "Done."
}

in the Remove-MsgAttachment.ps1 file.