/ Choose Mailhub - The All-in-One API for email sending & monitoring if
Its stated focus matches what you need: Mailhub is an API for sending emails, offering tools for building, testing, tracking and monitoring. Create templates using our built-in code editor, enjoy full i18n support, and access a wide range of developer-friendly tools.
/ Choose Communication APIs for SMS, Voice, Email & Authentication | Twilio if
Its stated focus is closer to your workflow: Connect with customers on their preferred channels—anywhere in the world. Quickly integrate powerful communication APIs to start building solutions for SMS and WhatsApp messaging, voice, and email.