22.214.171.124.4 OLE Attachments
This section describes the generation of MIME entities that correspond to OLE attachments. An Attachment object is an OLE attachment if its PidTagAttachMethod property ([MS-OXCMSG] section 126.96.36.199) is set to 0x00000006.
MIME writers SHOULD generate a MIME part that has "image/jpeg" for the value of its Content-Type header to represent an OLE attachment in a MIME message or MAY<98> use "image/BMP" for the value of the Content-Type header. MIME writers SHOULD<99> generate a description string for an OLE attachment by using the value of the PidTagDisplayName property ([MS-OXCFOLD] section 188.8.131.52.2.5) but ensuring that this value ends with ".jpg". The description string SHOULD be used as the name parameter of the Content-Type header, and the value of the Content-Description header SHOULD be generated with the same value.
A Content-Disposition header SHOULD<100> be generated in the same way as for ordinary file attachments, with the following exceptions:
The size parameter SHOULD NOT be generated.
The filename parameter value SHOULD be set to description string (see section 184.108.40.206.2.1).
The rest of the MIME part headers SHOULD be generated in the same way as for ordinary file attachments, as specified in section 220.127.116.11.2.
OLE attachments SHOULD NOT have the PidTagAttachDataBinary property ([MS-OXCMSG] section 18.104.22.168) set, so the MIME part body cannot be generated in the same way as for ordinary file attachments. Instead, the PidTagAttachDataObject property ([MS-OXCMSG] section 22.214.171.124) SHOULD be used. This property SHOULD contain a static rendition of an OLE object in metafile format, as specified in [MS-WMF]. MIME writers SHOULD<101> use this data to generate a Joint Photographic Experts Group (JPEG) image that represents this OLE object, and generate the MIME part body by using this image data. If image generation fails, the server SHOULD use a generic icon representing an attachment.