Sincerely: New Gmail Plugin Humanizes AI-Written Emails
Key Takeaways
- ▸Product detects and removes AI-specific language patterns (emdashes, repetitive phrases) that signal algorithmic writing
- ▸Privacy-first design with HTTPS encryption, no content retention, and browser-only API key storage
- ▸Founder's real-world testing with Fortune 500 CEOs showed positive engagement, suggesting the humanization approach is effective
Summary
Sincerely, a new Gmail plugin, aims to solve the growing problem of AI-generated emails sounding robotic and formulaic. The product removes telltale AI phrases (particularly emdashes and phrases like "not just"), adds realistic typos, and offers three intensity levels for humanizing email content. Founded by Ben (cratermoon), the tool was tested through cold outreach to Fortune 500 CEOs, with 4 out of 5 recipients replying—two responses contained typos and one called him by the wrong name, demonstrating more human-like behavior.
The product emphasizes privacy and security with end-to-end encryption, BYOK (Bring Your Own Key) API support, and explicit commitments not to log or retain email content. Users get 3 free email rewrites with all intensity levels available, and results are cached for instant reopening. The plugin integrates seamlessly into Gmail compose with simple one-click functionality and visual highlighting of changes.
- Three configurable intensity levels run in parallel with instant switching and cached results for user convenience
Editorial Opinion
Sincerely addresses a real and growing pain point as AI writing tools proliferate across workplaces—email recipients increasingly recognize and dismiss the distinctive patterns of AI-generated messages. By focusing on subtle humanization rather than wholesale rewriting, the tool offers a pragmatic solution for professionals seeking to maintain authentic voice while leveraging AI efficiency. The founder's guerrilla testing approach (cold emailing Fortune 500 CEOs) is clever marketing that also validates product effectiveness. This positions Sincerely well in the emerging category of AI-refinement tools that enhance rather than replace human judgment.
