block-disposable-email.com

I have never thought that the blacklist will bigger than maybe 10k domains. Now we reached more than 100k domains (not including subdomains), improved dea recognition (both in accuracy and speed), had no justified complaints about false positives, and a growing number of long-term customers.

Received 9 EUR from my first customer. What a great feeling ;-) Quickly other payments arrived. One of the most interesting learnings I ever had was that one of my customers said: "Well, as we see that you charge for what you are doing we trust that the API will be available for a longer term. In that case it makes sense for us to roll out for production."

Searched hours and weeks to find a suitable site that could help me avoid fake subscribers. Lists were outdated, incomplete, or full of false-positives. So I had to start my own dea recognition service.

After using it on my own I decided to grant access via an API. Free for everyone - mainly to understand if there is a market for such a service. After my first 1000 subscribers within weeks I turned the service into a freemium model which it still is.