In addition to the properties inherited from ItemType, MessageType exposes its own set of properties as listed Table 7-2.
Table 7-2. First-Class Properties on MessageType
An identifier that is used to link multiple messages together into a single conversation. All messages that have the same ConversationIndex property value are considered to be in the same conversation.
Describes the overall topic of a conversation. For most scenarios, the value of the Subject property is an appropriate value for the ConversationTopic.
This is the recipient information for who sent the message.
Represents the Internet message ...