This module is used for remote access to Voicemail boxes. For this, a password(PIN) is needed. Voicemail boxes without a password can not be retrieved. In addition, the module has a list that you can assign phone numbers directly to a voice mailbox.
This module is default in the T300/T500, when accidentally deleted from the system you can download the module here.
After installing the module, update the module to the latest version using the automatic update procedure:
Go to: Configuration - Server - updates - Press "Search now"