Email Processor doesn't honor content-disposition for .txt attachments

Attachments with a content-disposition of attachment should appear as attachments. They are currently being processed as inline.

Example headers:

------_=_NextPart_001_01CA64A6.614A9605
Content-Type: text/plain;
name="PM Transaction Reprint Journal.txt"
Content-Disposition: attachment;
filename="PM Transaction Reprint Journal.txt"
Content-Description: PM Transaction Reprint Journal.txt
Content-Transfer-Encoding: quoted-printable