You may be able to change your 'forward unconditional' settings using the Features menu.
Your system administrator can configure whether you can access this menu.
To do this during a call, press the PHONE key and then press Features.
To Switch On/Off – Select Forward Unconditional. Press On or Off to change the current setting. If no destination is currently set when you switch 'forward unconditional' on, the display jumps to the destination field.
To Select Which Calls as Forwarded – Select Call type. Press Change to see the different options. When the required option is displayed, press Save. The options are External Only, External and Group, Non Group Calls and All Calls.
To Set the Destination – Select Destination. Either press Edit and enter the number required or press ToVM for the 'forward to voicemail' option.
If you select voicemail as the destination, to enter a different destination, you first need to switch 'forward unconditional' off.