SendHQ

What is SendHQ?

SendHQ is an email API and shared workspace for developers and AI agents. It positions itself as one reusable email layer for everything that emails: products, services, AI agents, and people. The site describes it as "Email for everything you run" and "One email API" for sending, receiving, and managing email from one workspace. Instead of adding a separate email stack for each product, service, or agent, SendHQ provides accounts, domains, and identities that can send, receive, automate, and hand control to a human. It supports transactional email, inbound support, agent mailboxes, and controlled outbound.

How SendHQ works

SendHQ organizes email around accounts, domains, and identities. Each source—AI agent, product, service, or person—gets an identity that can send and receive through a shared platform. Outbound and inbound mail route through one system with account folders, domain dividers, and identity slots. Developers integrate once via REST API, inbound webhooks, scoped API keys, and delivery events. A typical send uses an API key, an idempotency key, and a from identity, then returns visible delivery events. The documented workflow covers verifying a domain, sending expected email, receiving replies, publishing typed templates, and inspecting delivery without hiding provider state. Inbound addresses, retained messages, private attachments, and conversations support replies and threading. The MCP server connects AI agents through Claude Code, Codex, or Claude Desktop with 59 typed tools and safety labels. An OpenAPI 3.1 specification supports clients, testing, discovery, and agent tooling.

Main features

• One API for transactional, inbound, agent, and outbound email.
• Accounts, domains, and scoped sending identities.
• Inbox + outbox, delivery and bounce tracking.
• Multiple verified domains and workspace API keys.
• Hosted templates with typed variables, previews, tests, and immutable releases.
• Inbound email: inboxes, routed messages, retained attachments, threading, labels, buckets, and spam/updates/importance sorting.
• AI agent integration: MCP server, 59 typed tools, and safety labels.
• Deliverability: provider events, sender-identity reputation, daily ramping, and automatic recovery.
• Suppressions and opt-outs for bounced, complained, or unsubscribed recipients.
• Server-side API keys and browser sessions.
• Standard JSON error envelope and retry-safe requests.
• Migration from Resend with compatibility boundaries.
• OpenAPI 3.1 and API reference.

Pricing

Two plan tiers are offered, each in Transactional or Marketing mode. Monthly or annual billing is available, with annual at 10% off. Prices are in USD through Dodo Payments.

• Starter Transactional: $9/month or $97.20/year; 50,000 emails/month, 25 verified domains.
• Starter Marketing: $19/month or $205.20/year; same allowances.
• Scale Transactional: $39/month or $421.20/year; 200,000 emails/month, 100 verified domains.
• Scale Marketing: $39/month or $421.20/year; same allowances. Every plan includes verified-domain sending, inbound email, delivery events, API access, inbox + outbox, delivery and bounce tracking, hosted templates, and workspace API keys. Scale adds priority support. No free plan exists. New workspaces get a controlled integration trial: 100 deliveries to your own account email or an AWS SES simulator address. There are no automatic overage charges; after the monthly allowance is used, further sends are rejected until the next month or a larger plan. Attachment transfer is capped at 10 GiB recipient-weighted transfer per month. Every To, Cc, and Bcc destination counts as one email. Annual plans keep the same allowances, metered per calendar month, not a year-long quota pool. Marketing adds a signed unsubscribe link, one-click unsubscribe headers, and suppression enforcement. Each sender starts at 2,000 recipients/day, rising automatically to 10,000 and then 50,000 after several days of clean sending. Accounts above a 3% bounce or complaint rate for two consecutive weeks are suspended.

Common use cases

• Transactional email: receipts, password resets, onboarding, alerts, and notifications.
• Inbound and support: support inboxes, replies, conversations, and threading.
• AI agent email: real inboxes, identities, controlled permissions, history, and human takeover.
• Controlled outbound: founder-led outreach; marketing mode is permission-based.
• Services and internal systems: background jobs, monitoring, billing, and scoped sending identities.
• Multi-product companies: one integration across domains, products, and workflows.
• Migration from Resend: map HTTP sends and account for compatibility boundaries.
• Template publishing: typed variables, previews, tests, and immutable releases.

Limitations

No free plan is offered; the controlled trial is limited to 100 deliveries to your own account email or an AWS SES simulator address. No automatic overage charges means sends are rejected at the monthly limit until the next month or a larger plan. Attachment transfer is capped at 10 GiB recipient-weighted per month. Daily sending starts at 2,000 recipients per sender and rises only after clean sending. Rising bounce or complaint rates lower or pause the sender, and accounts above 3% for two consecutive weeks are suspended. Annual billing does not create a year-long quota pool; allowances are metered monthly. Marketing requires permission-based sending, automatic unsubscribe links, and suppression enforcement. Billing is in USD via Dodo Payments, and the plan activates when the provider confirms the subscription. The pages do not list every webhook event, per-message attachment size, or all provider states. Documentation emphasizes explicit outcomes and not hiding provider state, so some operational status is exposed rather than abstracted. Resend migration has compatibility boundaries to review, and the MCP server is listed for Claude Code, Codex, or Claude Desktop, not all agent clients.

Summary

SendHQ is a developer-focused email API and shared workspace that unifies transactional, inbound, agent, and controlled outbound email under one integration. It uses accounts, domains, and identities to give products, services, agents, and people their own send/receive identity. Pricing starts at $9/month for Starter Transactional and $19/month for Starter Marketing, with Scale at $39/month for either mode; annual billing is 10% off. Every plan includes inbound email, delivery events, API access, hosted templates, and inbox + outbox, with no free plan and no automatic overage charges.