Due to a rapidly shifting technology and competitive market environment, Telecommunication and Internet Services are constantly subject to changes, creating new challenges and needs for the industry to keep generating revenues. A high level of customization is therefore identified as a key enabler for achieving customer satisfaction and improving their quality of experience. Enriching services with innovative approaches such as context-aware, adaptable and interactive mechanisms enable the vendors to deliver tailored and personalized experiences to its customers. This article presents a concept to integrate policy-based decision mechanisms into the architecture of a Next Generation Network (NGN)-based converged messaging enabler for supporting adaptive personalization and context-aware service delivery across heterogeneous networks and messaging technologies. The system reacts to context changes and makes real-time decisions about handling incoming messages according to the users' preferences. A prototype has been implemented as part of the Open SOA Telco Playground testbed at Fraunhofer FOKUS.