TIdDecoderMIME is a
TIdDecoder4to3 descendant that implements a decoder for MIME content encoded using the Base64 encoding algorithm. TIdDecoderMIME specifies the decoding table used by the decoder in
GBase64DecodeTable based on the Base64 alphabet in
GBase64CodeTable. TIdDecoderMIME also uses the special padding character "=" in the FillChar property.