HostName is a read-only string property that represents the host name for the local computer system. 

HostName uses the GetHostName() API for a protocol stack implementation to retrieve the value for the property. 

HostName is initialized and stored when a protocol stack instance is created for the Indy library in IdStackFactory. 

The format of a HostName value is dependent on the protocol stack implementation. It can contain a simple host name or a fully-qualified domain name.