An electronic communication system for sending, receiving, storing, organizing, displaying, and sharing electronic messages and content (e.g., text, image, audio, and video) is described. The electronic communication system provides a platform where users can communicate and share information with each other. For example, a user can create a conversation thread and invite other users to join the thread. They can send messages and other content via the thread and protect them by assigning different confidentiality levels and expiration restrictions. Furthermore, the electronic communication system provides a “two-dimensional” messaging mechanism, through which a user can select a particular message communicated with another user in a first Thread to follow up on that particular message with the same other user in a new Thread.