I don't miss email. One of the immediate benefits of Slack is someone can give a notice via Slack and the receiver can callback with an "acknowledged" or "noted

I don't miss email. One of the immediate benefits of Slack is someone can give a notice via Slack and the receiver can callback with an "acknowledged" or "noted". The callback is very important IMO because things get lost in email all the time. And yet you don't want 5 people to reply "noted".