I separate channels strictly. All internal communication — and anything with suppliers we work with structurally — runs through Slack, where threads keep every discussion traceable. Email is reserved for external contacts only, and there I apply Getting Things Done rigorously: no value or no action required, I delete it; if I can do it in two minutes, I do it now; if I need it later, I archive it. My inbox never exceeds 15 emails — it is literally my to-do list for external communication. The discipline isn’t the tool; it’s never letting the inbox become a filing cabinet.