If you have a voicemail message, you will see a badge displayed on the Calls icon indicating the number of pending voicemail messages.
The Desktop app offers two methods to retrieve your voicemail messages:
From the UC-One App toolbar menu
This will bring you to the voicemail display screen. Select the voicemail message you would like to retrieve and click the play button to listen to the message.
For each voicemail, the following actions are available:
For Voicemail customization options, select Voicemail in the Preferences menu.