Mautic

Mautic is an open-source marketing automation platform offering email, SMS, landing pages, and built-in lead scoring. You can self-host it on your own infrastructure or use Acquia's managed cloud service if you prefer hands-off hosting.

Best for organizations that need automation beyond email but want to own their infrastructure and data. Mautic offers significantly more than email-only tools and avoids Mailchimp's recurring licensing costs, though it requires more hands-on setup.