The MQMailTnefData structure describes a TNEF message, providing the binary TNEF data.
TNEF is a MAPI internal format that encapsulates the MAPI properties, and is used by the MSMQ Mail services (the MSMQ Exchange Connector and the MSMQ MAPI Transport) to send mail to recipients who are defined as rich-text recipients. Rich-text recipients are recipients who have the "Send to this recipient in Microsoft Exchange rich text format" check-box checked in their Exchange/MAPI address.
typedef struct MQMailTnefData_tag { ULONG cbData; //Size of the TNEF data. LPBYTE lpbData; //The tnef data buffer. } MQMailTnefData, FAR * LPMQMailTnefData;