Of those I only use Slack, so I can't speak for the rest of them, but isn't the whole point that you can silence channels that you're not interested in at that

Of those I only use Slack, so I can't speak for the rest of them, but isn't the whole point that you can silence channels that you're not interested in at that moment? Otherwise you might as well use AOL Instant Messenger. It is the absence of that feature that causes me to ignore e-mail.