The RingCentral for Desktop App (Windows) allows you to screen callers using the Screen Voice Mail feature. This comes in handy when you're expecting a particular call by sending everybody else to your voicemail.
To screen callers, click on Screen Voicemail
once you receive a call.
To interrupt a caller leaving a message, click Pick Up
. Otherwise, click Stop Listening
to end the call, but this will allow the caller to finish his message. You can then check the message at a later time under Voice messages.
Screening Calls with RingCentral for Desktop (Windows): Pre-Call Controls