Each Slack has at least one channel that you are automatically joined to upon sign in.

It’s typically named #general, and you cannot leave it.

It’s the one place that you can @everyone and blast a message to the entire membership, so use it wisely. It’s akin to using the “All-Page” button on an office phone system, where it blares out of each desk phone and interrupts the entire universe.

One recommendation is to rename the channel to something like #announcements-only and set the purpose and topic, and even consider restricting who can post to this channel.

Other ideas include muting the channel, if it’s too chatty. But remember, it’s the one place nobody can leave, and can never be archived. Consider carefully what you post here.