Hunting Group voice Mail directory Number

[ray_III]

Review/Modify: Hunt Group──────────────────────────────────────────────────┐
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│ Dir.No Assigned to the group │
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│ [ Add ] [ Remove ] [ Next ] [Previous] │
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│ Dir.No Assigned to the group : 2225 │
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│ Entity Number : 1 │
│ Priority Group + False │
│ CSTA Routing + False │
│ Preempter + False │
│ CUG List Number : -1 │
│ CUG Incoming Access + False │
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│ Voice Mail │
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│ Voice Mail Number : -------- │
│ Voice Mail Password : ---- │
│ Language Voice Mail : 1 │
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│ Pickup Private Call + False │
│ External Pickup Call + False │
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└──────────────────────────────────────────────────────────────

May I know what is the use of voicemail number under Hunting Group, How unattended calls will be routed to this voicemail number as same as Users can do?