Click on the "Admin" button on the lower left corner of the screen.
Click on the "System" tab, then select the "Voicemail" option.
Voicemail Menu Extension Number: This is the number to dial to access Voicemail. It is typically set to 999 or 9999.
Do not save Voicemails that are less than (seconds): This filters the Voicemail to be saved by the number of seconds. It is set to 2 seconds by default.
Voicemail quota, Gb: This quota determines the amount of storage that is reserved for Voicemail. Set to 5 Gb by default.
Automatically delete all Voicemails older than: Set to 30 days by default.