MIME parsing with PowerShell

<#
.SYNOPSIS
Parses a MIME email document into a CDO.Message object.

.DESCRIPTION
Reads the parameter MIME file into a CDO.Message (CDO for Windows 2000) COM object.
The returned CDO.Message object can be used to access the MIME file contents in decoded form.

.PARAMETER FileSpec
The file specification to be parsed, e.g. "C:\demo\test.eml".

.EXAMPLE
Get-ParsedMimeFile -FileSpec "C:\demo\test.eml"

.OUTPUTS
A CDO.Message object representing the parsed MIME document. See http://msdn.microsoft.com/en-us/library/ms526453(v=exchg.10).aspx

.LINK
http://msdn.microsoft.com/en-us/library/ms526453(v=exchg.10).aspx
[email protected]
#>
function Get-ParsedMimeFile([string] $FileSpec)
{
    # read MIME into a byte array
    $mimeBytes = [System.IO.File]::ReadAllBytes($FileSpec);

    # load byte array into an ADODB stream, which will act as data source for CDO
    $stream = New-Object -ComObject "ADODB.Stream";
    $stream.Open();
    $stream.Type = 1; # adTypeBinary, i.e. binary stream
    $stream.Write($mimeBytes);
    $stream.Flush();
    $stream.SetEOS();

    # create CDO.Message and assign stream as data source
    $message = New-Object -ComObject "CDO.Message";
    try
    {
        $message.DataSource.OpenObject($stream, "_Stream");
    }
    finally
    {
        $stream.Close();
    }

    return $message;
}

# DEMO
$message = Get-ParsedMimeFile -FileSpec "C:\demo\test.eml";

# dump subject
Write-Output "Email subject: $($message.Subject)";

# dump all parsed header fields
foreach($field in $message.Fields) {
    Write-Output "Field $($field.Name) => $($field.Value)";
}

# dump decoded email text body
Write-Output "Text body follows:`r`n$($message.TextBody)";

# dump decoded email HTML body
Write-Output "HTML body follows:`r`n$($message.HtmlBody)";