AI tools. Sorted by what actually ships.
MailTester.ai is a free email deliverability testing tool that analyzes SPF, DKIM, DMARC, and content quality. Users forward any email to a unique address and receive a comprehensive report with spam score, AI-powered content suggestions, and technical fixes. It helps marketers improve inbox placement and open rates by identifying spam triggers and optimizing subject lines.
Document CoPilot is an AI-powered writing assistant that integrates directly into Google Docs. It provides in-line comments and suggestions for improving grammar, tone, structure, and argument. Users share their Google Doc with the Copilot, which then joins and collaborates like a human editor. It uses LLMs like Claude and GPT to offer thoughtful feedback without wholesale rewriting. The tool is free to demo, then charges a small fee per set of comments via Stripe, with no subscription. It supports various document types but only Google Docs currently.