MailChimp is a cloud-based email marketing platform that allows businesses to create, send, and track email campaigns. It has a powerful API that enables integration with various third-party applications and services.
ConvertKit is an email marketing automation platform aimed at professional bloggers, course creators, and online business owners. It allows users to create and segment email lists, design custom email templates, and automate email sequences, all while providing robust analytics and integrations with other tools.