You can do this with embossed quite simply.
First create a shortcode say *66 for example. Feature: Voicemail Collect Telephone Number will be #(username. For example if the user was JoeSmith the Telephone number would look like this "#JoeSmith" Make sure it is encased with " ". Also it is the Name field not full name you use. Case sensitive..... Don't forget the #
Next create a phantom user named whatever you want example FWDjoeMBX
Next go to the forward tab on the phantom user tick Forward Unconditional, Forward Hunt Group calls, Forward internal calls. In the Forward Number field put the new shortcode. For this example *66
Next make a new sequential Hunt Group (or Group R9+) name it whatever you want. For example Overflow Joe MBX, Then add the Phantom user (FWDjoeMBX) as its only member
Next set your original Hunt Group to collective or collective call waiting. Voicemail off. Queuing off. No answer time to whatever you desire before it overflows to the intended users mailbox. In our example we will user 18 seconds
Next set the Original Hunt Group overflow tab. click add and add the new Hunt Group (Overflow Joe MBX)in our example. Overflow time -Off, Overflow Mode -Group, Immediate Overflow -Off.
So the call would flow like this...
Call to Original Group Rings desired phones for 18 seconds >>>> Original Group overflows to group named, Overflow Joe MBX>>>> Overflow Joe MBX Groups is sequential and has ONLY one user. FWDjoeMBX>>>>> User FWDjoeMBX is set to Forward Unconditional all internal and Hunt Group calls to *66>>>> *66 is a shortcode that calls directly to leave mail into Joe Smith's mailbox.... TADA!
Works like a champ. been doing it this way since R5. Just did it on a R9.0.4.
Brian