16 articles
The most comprehensive guide to email CAPTCHA and challenge-response email systems. Covers history, how modern systems work, technical deep-dives, privacy considerations, economic analysis, and the future of inbox protection.
The number one concern founders have about inbox protection: "What if I miss an investor email?" Here's how sender verification actually works for founders — and why the right emails still reach you.
A step-by-step guide to automatically archiving cold emails in Gmail using native filters, Google Apps Script, and dedicated sender verification tools. Stop cold emails without losing legitimate messages.
Email was designed for communication between people who know each other. AI has turned it into an advertising channel. It's time to fix the inbox by changing who gets access to it.
Gmail doesn't have a built-in "block unknown senders" feature. But there are workarounds — from filters to third-party tools — that achieve the same result. Here's how.
Challenge-response email systems have existed since 2003. They failed the first time due to friction and poor UX. In 2026, modern CAPTCHA technology is making them work. Here's the full history.
A 30-day experiment using email CAPTCHA to protect a founder's Gmail inbox. The results: 73% fewer emails requiring attention, and only one genuinely missed message.
Founders and CEOs receive more cold email than anyone. Here's how the best operators manage 200+ emails per day without letting email consume their schedule.
A comprehensive comparison of every major Gmail inbox protection approach — from built-in features to third-party tools — with recommendations based on your specific inbox problem.
SaneBox isn't the only option for managing Gmail overload. Here are five alternatives — from AI sorting to sender verification — compared by approach, effectiveness, and price.
Superhuman helps you process email faster. Captchainbox stops unwanted email from arriving. Here's when speed matters — and when volume reduction matters more.
Hey.com's Screener and Captchainbox both gate unknown senders — but one requires manual review and a new email address, while the other automates everything on your existing Gmail.
Captchainbox verifies senders with CAPTCHA. SaneBox sorts email with AI. Two fundamentally different approaches to the same problem — here's how they compare.
A practical comparison of the best tools for stopping AI-generated cold emails in Gmail — from sender verification to AI filtering to full inbox overhauls.
A CAPTCHA for your email inbox works the same way website CAPTCHAs do — it proves the sender is a real human, not a bot. Here's how it works and why it's becoming the new standard.
AI-powered outreach tools are flooding inboxes with personalised cold emails that look real. Here's how to stop them without cutting off genuine contacts.