A MIME handle is a list that fully describes a MIME component.
The following macros can be used to access elements in a handle:
mm-handle-buffermm-handle-typeContent-Type of the part.mm-handle-encodingContent-Transfer-Encoding of the part.mm-handle-undisplayermm-handle-set-undisplayermm-handle-dispositionContent-Disposition of the part.mm-get-content-idContent-ID.