I built 17 free email tools. What should I build for tool #18?

Hey everyone! 👋 Today I launched Mail Tool Hub, a completely free directory of 17 email deliverability and verification utilities (spanning everything from an AI Spam Trigger Checker to SPF/DKIM validation).

My goal is to make this the ultimate, centralized toolbox for founders, marketers, and developers so no one has to pay a $30/month subscription just to check a DNS record or clean a list.

I want to keep expanding the platform this weekend. What is the one specific email tool, checker, or script you desperately need but isn't in the Hub yet? Drop your most niche, frustrating, or highly-needed email workflow bottlenecks below.

I will build the best ideas and add them to the directory! 🚀