cpegeno,
Here is the information straight from the F1 help document.
Programming a Specific System Forwarding Path
The Forwarding Path option is located in:
System\Devices and Feature Codes\Phones\Local\<phone>.
System\Devices and Feature Codes\Phantoms & Hot Desk Profiles\<phantom or hot desk profile>.
Double-click on the forwarding path to view the following options:
Forwarding Path
Ring Principal Once
Phone Conditions (Busy, DND, No Answer, and Immediate)
System Conditions (Day and Night Mode)
Forwarding Call Types
System Forwarding Call Types
This option is located in System\Devices and Feature Codes\Phones\Local\<phone>\Forwarding Paths.
The types of calls that can be forwarded are listed below. The forwarding phone can be programmed to forward any or all of these call types. (In the default state, call routing, ring-in, DISA, and transferred calls are enabled.) Determine the types of calls that will follow the forwarding path by enabling each desired call type.
To enable a flag:
Select the current value and then select the check box to place a check in it.
Press ENTER or select another field to save the change.
To remove the check and disable the flag, select the check box again.
Call Routing Table: Outside calls received through a call routing table (including DID (or DDI for Europe) and E&M calls, but not including DISA calls)
CO Ring-In: Ringing outside calls (including calls received through network connections)
CO Transfer/AA/VM: Transferred outside calls (including automated attendant and voice mail transfers and transfers from other nodes)
CO Recall: Recalling outside calls (including calls from other nodes)
DISA: DISA calls (including DISA calls received through a call routing table)
IC Calls: Intercom calls (including calls from other nodes)
NOTE: Call forwarding paths are checked in numerical order when they apply to the same call type (for example, multiple forwarding paths for outside calls). If one forwarding path is for the "No Answer" call condition, it should be last on the list of forwarding paths for the phone. If No Answer is the condition in the first path, the system will always wait for the System Forward Initiate timer to expire before forwarding, even if the phone is in do-not-disturb mode or busy.
So, if you set the call types that you don't want to go to voicemail to NO and the ones you do to YES then you will be good to go.
Thanks,
TE