This communication, marketing and stakeholder engagement strategy details the methods to be used to present Science Mesh to the key target audience of the CS3MESH4EOSC project, composed of researchers, industry, developers, policy makers, and citizens. The strategy is divided into 3 main project phases. While the first phase is mainly devoted to developing and testing the Science Mesh as the main asset of CS3MESH4EOSC, the second stage revolves around inviting early adopters from both academia and the industrial sector. The third phase is focused on enlarging the Science Mesh community as a whole for its full deployment into the market. Chapter 3 contains the draft communication and stakeholder engagement plan which focuses on 5 main implementation steps: Preliminary Communication & Marketing Strategy, second version of the Communication & Marketing Strategy, Stakeholder engagement for adoption of Science Mesh, Community Engagement, and Impact & Sustainability. The deliverable also provides an overview of the new version of the project website that will be made public at the end of September 2020, and identifies all the channels to be used and the key activities to be deployed to ensure sound and effective communications. A specific engagement strategy is identified for each target audience and there is a detailed recruitment plan for each stakeholder, which includes a set of KPIs to track the work in progress. The same KPI-driven approach is applied in the marketing and communication plan, with results achieved being analysed both monthly via a ���Flash Report���, and by way of automated software that visualises and tracks the communication and dissemination results.