According to my info is the voice message in an overflow from a hunt group always spoken and then the call is disconnected. It says in my manual that an overflow message is a "DVU Drop". DVU means Digital Voice Unit.
So it works accordin to the manauls...
With the LDK series (e.g. LDK-24) it works different. It is possible to overflow to e.g. menu function.
With the GDK-16 overflow can be made to a station, hunt group, speed dialing number or DVU drop.
///doktor