The project manager should be the one communicating the project details within various teams. Communication being an important part of the project, I believe most of the communication within a project team should be carried out via emails and face-to-face. When having to communicate information to all of the team members or sending a detailed information which would need discussion having a face-to-face meeting would be the most ideal. Otherwise, communication can be made through emails by the project manager to the team member/s as and when needed. For emergency situations, phone calls may be used with the call logs being added to the reports.