The idea of the project was at first to create a API for validating email addresses to determine whether they are legitimate or they are fake/disposable. After some initial reachout to potential customers to validate it, I reached the conclusion that the demand for such a solution was not there.
Then, an initial pivot happened: from the conversations I outlined a certain complaint that was somewhat common among the contacted people: getting bombarded by unsolicited emails attempting to sell them all kinds of products and services (mainly SEO and outsourcing services). The pivot for SpamLabs was toward the direction of an email filter for blocking such content. After some iterations on the implementation using OpenAI, I managed to get a working solution where only the AI API costs were ~10€ per month in the average case, so the smallest plan ended up being ~20€. After some more outreach with this new solution I saw that the demand isn't there either for this new approach: these emails were at most a mild annoyance which was fixed with a few seconds of time investment each day. The value was nowhere near the 20€ prince point I was asking.