Transferring calls from your phone:
https://support.ringcentral.com/article/Transfer-Call-Voicemail-using-Polycom-VVX-Device.html
Setting default transfer method from your phone:
https://support.ringcentral.com/article/Deskphones-Polycom-Phones-Change-Default-Transfer-Type.html
Voicemail notifications to email:
https://support.ringcentral.com/article/9740.html
Turn off Parked Call Notifications:
https://support.ringcentral.com/article/Polycom-VVX-Phones-Ringing-Incorrectly-for-Parked-Calls-and-Presence-Notifications.html