Internet Direct (Indy) Version 9.0.1 Beta
TIdMessageParts.AttachmentEncoding
Identifies the default encoding mechanism used for a message part.

property AttachmentEncoding: string;
Description
AttachmentEncoding is a String property that identifies the encoding mechanism used for attachment message parts in the message. Changing the value of AttachmentEncoding for the message part collection also updates the default encoding used for all message parts in the collection, and updates MessageEncoderInfo to the encoder that handles the AttachmentEncoding .

Default value for AttachmentEncoding is 'MIME', as assigned in the Create constructor.