InitializeHeaders is a virtual procedure in
TIdMessageEncoderInfo that Specifies a method for generating RFC 822 message headers for an instance of
TIdMessage. Descendant classes, like
TIdMessageEncoderInfoMIME,
TIdMessageEncoderInfoUUE, and
TIdMessageEncoderInfoXXE should override the method to provide support for generating message headers specific to the giver encoder type.