SendHQ

SendHQ is an email API for product teams and AI agents that need one coherent workflow for product communication. It supports transactional sending from verified domains, inbound email, delivery-event visibility, workspace-scoped API keys, and an agent-facing public REST API. Product teams can use the same service to verify sending domains, send transactional messages, receive replies or other inbound messages, inspect delivery outcomes, and manage API access without splitting these jobs across unrelated tools. The workflow is designed around observability and sender-safety controls, so developers can see delivery events and keep API credentials scoped to the relevant workspace. SendHQ is useful for SaaS products, internal tools, and agent workflows that require programmatic email with clear operational visibility. Its public documentation includes an OpenAPI specification and agent-facing guidance, making the API surface easier to inspect before integration. The service is a paid subscription with no public free tier or free trial. Transactional Starter begins at nine dollars per month, Transactional Scale at twenty-nine dollars per month, Marketing Starter at nineteen dollars per month, and Marketing Scale at thirty-nine dollars per month. SendHQ does not promise guaranteed deliverability. Instead, it provides the infrastructure needed to send from verified domains, receive email, view delivery outcomes, and manage scoped keys in one place. Teams can review the public website, API specification, privacy policy, terms, and agent documentation before deciding whether it fits their email workflow.