TIdMessageEncoding is an enumerated type that indicates the encoding scheme used for an RFC-compliant Internet message. TIdMessageEncoding is the type used to represent the
TIdMessage.Encoding property and indicates that the message should be transferred as MIME-encoded multipart, or UU-Encoded multipart message.
TIdMessageEncoding is used to determine the encoders used when creating and preparing headers and attachments for transporting an Internet message.