It is possible that a mattermost user disables it so that he cannot send messages to other users or receive them, but only to read old messages, that is, read only.
Hi @racso ,
sorry for bumping this old post, but this is not possible. You can disable the ability for your users to create direct- or groupmessages with others and you can also disable the ability to create channels, but if they’re part of a channel, they’re also allowed to post there. The free edition does not support read-only channels.