I’ve spent $400/year on an email app for six years straight because it consistently cuts my email time down to ~30 minutes a day—so I can actually run the business. In this video, we put four email clients head-to-head across five criteria: purposeful design, speed & productivity, AI assistance, follow-up, and team collaboration. We tested the fully paid versions of Gmail, Notion Mail, Spark, and Superhuman, and we’re blunt about what you gain (and lose) at $0, ~$10, and ~$40/month. Design-wise, Gmail is visually cluttered and distraction-heavy, and it’s not built for focus. Notion Mail is cleaner (desktop-only for now) but has friction in triage and the compose window can cover what you’re referencing. Spark improves focus and adds some team features, but inbox sorting is limited and parts of the UI are still busy. Superhuman is the only one that feels designed for deep work: minimal UI, inbox splits, and true keyboard-first flow. From speed to AI to follow-ups, Superhuman kept winning because it reduces friction: natural-language snooze/send later, fast quoting, snippets with analytics, surprisingly seamless offline mode, AI that actually learns my tone, and read receipts + auto-drafted follow-ups. If you’re a high-volume operator or a team, that’s why paying for email becomes a no-brainer.