Outlook MSG files are also ole files.
Here is a new plugin (plugin_msg.py) for oledump that identifies streams in MSG files based on the 8-digit hexadecimal codes in the stream name.
The first 4 hexadecimal digits identify the content of stream, and the next 4 hexadecimal digits identify the type of the stream.
oledump_V0_0_32.zip (https)
MD5: 10D8995B6AF5C783B1F8AAF70B8FDB03
SHA256: 0E38BAF12B066A100F97F3362402E1999F2DE223A09491E3D44C20EA4BDBD8AB
Didier Stevens 