Complete these steps in order to completely disable the ability to dial an extension:
- In Cisco Unity Tools, and under Administration Tools, open the BulkEdit.
- Choose Subscriber, and click Next.
- Choose All Subscribers, and click Add Subscribers to Grid, choose all, and click Next.
- Click Greetings, and then choose the desired greeting. Under Allow User Input, choose False. Click Next.
- Update Subscribers, and click Exit.
Complete these steps in order to disable the caller input for the subscribers, but still leave the option to dial some specific digits, such as 0:
- In Cisco Unity Tools, and under Administration Tools, open the BulkEdit.
- Choose Subscriber, and click Next.
- Choose All Subscribers, and click Add Subscribers to Grid.
- Once they are on the grid, choose the specific users for whom to disable the caller input, and click Next.
- Click the Caller Input tab, and for each digit to disable, choose True under Lock Key. Click Next.
- Update Subscribers, and click Exit.
For more information and troubleshooting tips: