One-Sender Inbox

Self-creating email inboxes that lock to one sender and bounce all spam

Problem

Users are overwhelmed by spam and marketing emails, and regular inboxes are hard to manage. Someone built an email app that only accepts one sender per inbox, but no product serves mainstream users yet.

Solution

An email service that creates a new inbox on-the-fly when you use any prefix@yourdomain; each inbox locks to the first sender domain (or email address) and bounces everyone else; temporary inboxes expire after a set time (e.g., 24h, 7 days) and bounce all future mail.

Users

Anyone plagued by spam, privacy-conscious users who want to isolate emails per service, freelancers and small business owners.

MVP

Custom domain email; auto-create inboxes; lock to first sender and bounce others; temporary inbox expiry with bounce; simple web UI to view emails.

Revenue

Freemium: limited inboxes free, paid tier for more inboxes, custom domain, and permanent retention; or annual subscription.

Why now

Email privacy and spam are growing problems, and existing clients lack such aggressive anti-spam strategies; indie developers can build on open-source mail servers quickly.