Coordination of message thread groupings across devices of a communication system

A system that can coordinate user interface formats having customized threads comprising messages from a common thread. Each client device can be managed by a data structure that defines thread containers, where individual thread containers define threads and topics for each thread. Each thread can also be associated with unique groups of messages. The data structure can cause each client computer to display different user interface formats, with each format showing different threads for each user. Individual devices can control displayed threads according to a topic limit so that displayed messages can be limited for optimizing the use of a display screen and other computing resources. The system provides more granular control of user interface formats to allow users to separate messages of high-priority topics.