IMimeMessageHeaders Property

HeaderList Headers { get; }

Property Value

Represents the list of headers for a message. Typically, the headers of a message will contain transmission headers such as From and To along with metadata headers such as Subject and Date, but may include just about anything.

Tip
To access any MIME headers such as ContentType, ContentDisposition, ContentTransferEncoding or any other Content-* header, you will need to access the Headers property of the Body.

Reference