Inumbo is a straight-forward and minimalistic anti-spam service for organisations and individuals that have their own email server. It activates the moment you register your domain. If you control your own DNS, you're up and running in minutes. Inumbo is transaction safe, and reject spam with a CAPTCHA-based self-service false positive report tool. It supports modern technologies like DMARC verification and IPv6.
All it takes is a username and a password.Sign up