2.1.3.3.9 attBody Attribute
The attBody attribute MAY<1> be supported.
The attBody attribute is a message-level attribute that maps to and from the PidTagBody property ([MS-OXCMSG] section 2.2.1.56.1).
The data for this attribute is stored as a string with a terminating null character.
For more details about how the TNEF Writer handles this attribute, see section 2.2.3.6.