Synchronoss Announces More Than 30 Million RCS-Based Messaging Subscribers in Japan Leveraging the Synchronoss Advanced Messaging Platform, NTT DOCOMO, KDDI, and SoftBank Deliver Cross-Operator Advanced Messaging Service Enabling Users and Brands to Communicate, Interact, and Transact GlobeNewswire December 21, 2022 The current milestone represents a 62 percent increase in subscribers since Synchronoss.