TElCustomSimpleSSLClient.Active property

Specifies whether the session has been established and the data can be sent and received.

    This read-only property returns True if the secure session was established, and the client can send data. If the client can't send the data now, False is returned. The client should check the value of the property before calling SendData.
    However, if the connection is lost on the socket level, there is no way to find out that the connection has been closed, and Active property can still be True. By design of TCP/IP protocol, the only way to check the actual connection state is to send something and get an error if the connection is closed.