With the proliferation of a wireless network support and the advances of mobile devices, there is a growing need of making it available for a wireless network as well. Low bandwidth is one of the major issues that should be considered for extending a synchronous collaboration system developed for a wired network to support a wireless network. We propose a priority-based message synchronization scheme, exploiting the relaxed synchronization. The proposed scheme leverages the fact that mobile users need not have the exactly same view as the users in a wired network since they usually have a limited screen size and thus focus only on part of a whole document. To verify the proposed scheme, we simulate collaborative work using network simulator ns-2. We measure the notification delay of messages and processing overhead in the proxy as the number of clients increases. As a result, it shows that most interested message delivered in a bounded time and the computational overhead for filtering is acceptable.