Offer an onboarding bot
An on-boarding bot helps new users to on-board into a work environment. In every channel a new team member enters the On-boarding Bot will send a message explaining the channel, what is done there, how the team member can get involved, whom to contact etc. This would help organizations and teams to work more efficiently.
This seems to be a duplicate of the popular https://mattermost.uservoice.com/forums/306457-general/suggestions/13702560-preinstalled-matter-bot. Consider upvoting it!
Marcus Mangelsdorf commented
It could also explain, how replying to threads work, since most of our users *always* create a new thread instead of answering/commenting...