TElMessagePartHandler is a base class for TElMessagePartHandlerSMime.
TElMessagePartHandler is a base class for additional part handlers implementation.
TElMessagePartHandler provides common interface with empty functionality for handler classes. It does not affect final result of message parsing and assembly.
Descendants of TElMessagePartHandler should implement only the methods they need.
Although it is possible to create an instance of TElMessagePartHandler, do not use it directly in your applications.