Real email inboxes for your AI agents

Three things. First, a real dashboard on every plan including Free; most agent email APIs are API-only, so you can’t see what your agent actually did. Second, built-in security: every inbound email is scanned for prompt injection and scored before your agent acts on it, and nobody else does this. Third, included capacity: Dead Simple’s $29 Pro plan includes 100 inboxes, while AgentMail’s $20 plan includes 10 and bills $2 per extra inbox on top, so 100 inboxes there runs about $200. Dead Simple’s ladder is $0, $5, $29, and $99. We also ship drop-in tools for LangChain, CrewAI, AutoGen, LlamaIndex, and the OpenAI Agents SDK, and deliverability is actively managed with per-inbox reporting, not a shared black box.

Yes. Dead Simple is fully bidirectional. Inbound emails arrive as structured JSON via real-time webhooks (HMAC-signed) or WebSocket streaming, so your agent can react instantly. WebSockets work behind firewalls with no public URL needed. You also get automatic threading, reply parsing (quoted text is stripped), and conversation history — all through the API. Every inbox also comes with standard IMAP credentials, so you can connect with any email client or library if your workflow needs it.

Yes. Every inbox comes with standard IMAP and SMTP credentials, available via the GET /inboxes/{id}/credentials endpoint. Connect with any email client (Thunderbird, Apple Mail, Outlook), use Python’s imaplib, or plug into legacy tools that speak IMAP/SMTP. IMAP runs on port 993 (SSL/TLS) and SMTP submission on port 587 (STARTTLS) at mail.deadsimple.email. Use the REST API, IMAP/SMTP, or both — it’s your choice.

SPF, DKIM, and DMARC are configured automatically for every inbox — on shared domains and custom domains. Deliverability is our focus, not an afterthought: sender reputation is actively managed for inbox placement, and you get per-inbox reporting on delivery, bounces, complaints, and spam placement so you can see exactly what’s landing. We handle bounce classification and automatic suppression of hard-bouncing addresses for you. You don't need to configure any DNS records to start sending on the shared domain. When you add a custom domain, we generate the required DNS records and verify them for you.

Yes. Multi-tenant workspaces let you create isolated namespaces for each of your customers, with scoped API keys that only access their own inboxes. Workspaces are available on Pro ($29/mo) and Scale ($99/mo). You can also use bulk inbox creation to provision many inboxes at once. Competitors typically charge $200/mo or more for multi-tenant isolation.

We provide typed, async-ready SDKs for Python, TypeScript, and Go, plus a CLI tool. For agent frameworks, we have drop-in integrations for LangChain, CrewAI, AutoGen, OpenAI Agents SDK, and LlamaIndex. We also have an MCP server for Claude and Cursor, compatible with Google ADK. Most competing APIs don't ship any framework integrations at all.

Gmail and Outlook actively suspend accounts that send programmatically — it's a violation of their terms of service. Google OAuth requires 200+ lines of boilerplate and constant token management. And per-seat pricing ($7-8/mailbox/month) makes 100 mailboxes cost $700-800/mo. Dead Simple gives you 100 inboxes for $29/mo with simple API key auth and no suspension risk.

The Free tier is your trial. It includes 5 inboxes, 5,000 emails per month, webhooks, and dashboard access with no time limit. Build and test your full integration before you need to scale. No credit card required.

Yes. Sign in with Dead Simple is a free OpenID Connect provider at id.deadsimple.email where the identity is the agent’s inbox. Any app that accepts a generic OIDC provider (Auth.js, Better Auth, Clerk, Auth0) can let an agent sign up and sign in, and the agent authenticates with the API key it already holds, so there is no key ceremony. The app receives a stable sub, a verified email address, agent: true and owner_verified. Included on every plan, including Free.

Yes. Call a priced route with no credentials and it answers 402 with a price. Pay inline with x402 (USDC on Base, Polygon or Solana) or, for inbox creation, with a Stripe card via the Machine Payments Protocol, then retry. An inbox costs $1.00 and includes 1,000 sends per month, a send is $0.01, and a read is $0.005. The first paid inbox returns an API key, so the wallet becomes an account. See pay per request.