If callers can not leave a message, it is likely due to two features (Call Forward No Answer and Call Forward Busy) that need to be enabled to allow callers to leave a message.
To enable these features, follow these steps.
For Call Forward No Answer, pick up the line, dial *92 and hang up. For Call Forward Busy, pick up the line, dial *90 and hang up.
After enabling both features, try calling your office number from a different line and confirm if the call goes to voicemail.
