1. Log in to the manager portal
2. Click on the Users button on the top

3. Navigate to the User wanting to clear the VM messages and on the right-hand side click on the Pencil Icon and then the Voicemail option

4. Navigate down to the Number of Messages and click on Clear Messages to delete all the voicemail messages for that user.
NOTE: The Number Of Messages does hold fax messages but the clear messages option ONLY clears voicemail messages.