EIdException = class(EIdExceptionBase);

EIdException is an EIdExceptionBase descendant that represents a common ancestor for exceptions raised in the Indy library. All exceptions explicitly raised by the Indy library must descend from EIdException. This is the class that differentiates Indy exceptions from non Indy exceptions. 

Use EIdSilentException for exceptions that can be ignored in the IDE. 

Use EIdWrapperException for non-Socket exceptions raised by the .Net framework.