The market for email deliverability is substantial, as many businesses rely on email for communication and marketing. An API-first approach for domain verification without SMTP relay offers a streamlined and potentially more robust solution than traditional methods, making it feasible for a small team to build an MVP. While there are existing email service providers and deliverability tools, a dedicated comparison platform focusing on API-first verification without SMTP relay presents a niche that might be underserved. Localization is straightforward as email deliverability is a global concern, and payment/regulatory aspects are generally consistent across regions for this type of service.