Hi John. It turns out that the current functionality of the plugin is to display the last week of messages.
If this feature is important to the way you or your clients want to use your RingCentral account, I highly recommend making an idea post on this community site. If other RingCentral users also like this idea, they can vote on it. This is where many new features for our services can start out. We do have a helpful
walkthrough page for submitting a new idea in the RingCentral community.