Best Email API in 2026: An Engineer's Honest Comparison

Why this list is different The "best" email API depends entirely on what you're building. A side project optimizing for the free tier needs different things than a Series B SaaS sending two million transactional emails a month. This post grades eight providers against the criteria that actually move the needle in production, and tells you which one to pick for which use case. Most roundups in this category read like vendor brochures. Every product is "robust, reliable, and developer-friendly." N