AgentEmail: Email Inboxes for AI Agents, Explained

AgentEmail is an API that gives AI agents their own email inboxes. One API call creates a real address on its domain, such as hello@agentemail.co, and your agent can then read threads, receive new mail by webhook and, according to the company, reply like a person would. Its own tagline is that it’s “not AI on top of email” but “email built around your AI.” It isn’t the same company as AgentMail, a better-known service with a nearly identical name.

The quick answer: AgentEmail is a young, simple inbox API with a generous free plan and typed SDKs for Python and TypeScript. Its public documentation is thin, though: it covers creating inboxes and reading mail, but not sending or replying. Confirm that part works for your use case before you build on it. A clear disclosure: we make CarlyEmail, a direct competitor. We’ve separated what AgentEmail’s own pages say from our view, and put our comparison in its own section so you can weigh it accordingly.

AgentEmail at a glance

Checked against AgentEmail’s site, docs, pricing, terms and package registries on November 12, 2026.

AgentEmail is not AgentMail

The names cause real confusion, so it’s worth being precise. AgentEmail (agentemail.co) is the company this page covers. AgentMail (agentmail.to) is a separate, Y Combinator-backed company that raised a $6 million seed round in 2026 and runs one of the best-known inbox APIs for agents. We found nothing linking the two.

If you came here looking for AgentMail, our AgentMail explainer and AgentMail alternatives cover it in detail.

Why AI agents need their own inbox

Most email APIs were built for one-way sending: receipts, password resets and newsletters. Services like SendGrid and Mailgun are excellent at getting a message out, but they weren’t designed for an agent that has to read a reply, keep a thread straight and answer in context. AgentEmail’s FAQ makes the same point: “SendGrid and Mailgun are designed for sending transactional emails… AgentEmail is built for receiving and managing email conversations.”

An agent with its own address can do several things it otherwise can’t:

• Sign up for things. Many services require an email address and a verification code. A browser agent with an inbox can register, receive the code and finish signup on its own. Our guide to agents and email verification codes covers this pattern.
• Hold conversations. Customers, vendors and colleagues can email the agent directly, and it can reply in the same thread.
• Process documents. Invoices, receipts and forms arrive as attachments the agent can read and extract data from.
• Act as a separate identity. The agent’s mail stays out of your personal inbox, and its permissions can be limited to that address.

For a longer explanation, see what it means to give an AI agent an email address and our overview of email APIs for AI agents.

How AgentEmail works

AgentEmail’s documentation describes a small set of concepts:

• Inboxes. Each is a real address at @agentemail.co. You choose the part before the @, and AgentEmail “handles delivery, storage, and retrieval.” Inboxes keep their mail until you delete it.
• Threads and messages. Mail is grouped into conversations, “the same model used by Gmail and most modern email clients.” Reading a thread returns each message’s sender, subject, HTML and plain-text body, and attachments.
• Authentication. API keys start with aem_ and can be set to expire after up to a year.
• Webhooks. When new mail arrives, AgentEmail posts an email.received event with the inbox, thread and message IDs, sender and subject. Your endpoint must answer within 10 seconds, and failed deliveries are retried with exponential backoff.

The Python SDK comes in synchronous and async versions, and there’s a TypeScript SDK and a plain REST API. The docs include short examples of wiring AgentEmail into a LangChain agent and an OpenAI function-calling workflow, so an agent can check its inbox as part of a task.

AgentEmail’s FAQ adds that it isn’t integrated with Gmail (“We provide fully managed email inboxes that you control via API”), that it supports attachments, and that it “manage[s] SPF, DKIM, and DMARC records” and monitors sender reputation to keep mail out of spam.

What the docs cover, and what they don’t

This is the most important thing to check before choosing AgentEmail. Its homepage lists a broad feature set: threads and replies, attachments, real-time events, custom domains, “SDKs + MCP,” semantic search and data extraction. Its use-case examples include an AI executive assistant that books meetings and a support agent that routes incoming mail.

The public API reference is narrower. As of November 12, 2026, it documents five endpoints:

There’s no documented endpoint for sending a new email or replying to one, and no public documentation for the MCP server, custom domain setup, semantic search or data extraction. That doesn’t mean those features don’t exist. They may be in the dashboard, in private beta or simply undocumented. But if your agent needs to send mail, ask AgentEmail to show you the send and reply API before you commit.

AgentEmail’s plans

AgentEmail’s pricing page lists four tiers.

Every plan includes REST API access, webhooks and API key management. Startup adds priority support and higher rate limits. Enterprise adds dedicated infrastructure, SLA and uptime guarantees, custom contracts and, according to the page, “SOC 2 (coming soon).” Annual plans are billed upfront. The free plan’s 3,000 emails a month is generous for a prototype.

The company behind it

AgentEmail is early. Its Python and TypeScript SDKs were first published to the public package registries in May 2026 and are at version 0.1. Its blog has one post, from May 31, 2026. Its terms of service carry a “last updated” date of May 17, 2025. We couldn’t find the names of its founders or team on its site, and found no announced funding.

None of that is a reason to rule it out. Plenty of good developer tools start small. But it does mean you have less to go on than with an established vendor: no public track record, no published security certification yet, and no team you can look up.

Terms and data

AgentEmail’s terms are short and fairly standard:

• You own your mail. “You retain ownership of all content (including email data) processed through your inboxes,” and AgentEmail gets a limited licence to process it “solely to provide the Service.”
• No uptime guarantee by default. The service is provided “as is” and “as available,” and AgentEmail doesn’t “guarantee uninterrupted or error-free operation.” Enterprise plans list SLA guarantees.
• No spam or phishing. Bulk unsolicited email, malware and deceptive messages are banned, and AgentEmail can suspend accounts “in our sole discretion” for violations.

How to evaluate any agent email provider

Whichever service you pick, these are the questions that separate a demo from something you can run in production:

1. Can the agent send and reply in-thread through the API? Reading mail is half the job. Replies need to keep the thread together so recipients see one conversation.
2. How do you find out about new mail? Signed webhooks are the baseline. WebSockets or event streams help when you don’t want to expose a public endpoint.
3. Can you use your own domain, and who handles deliverability? Mail from a brand-new address on a shared domain is more likely to land in spam. Ask about SPF, DKIM and DMARC, and whether there are warm-up limits.
4. What are the sending limits? Monthly caps are common. Daily and per-minute caps matter more, because they decide whether a busy afternoon breaks your agent.
5. What protects you from bad inbound mail? Anyone can email an agent, and a cleverly written message can try to talk it into something. Allow lists, block lists and human approval for sensitive actions all help.
6. Can it serve your customers separately? If you’re building a product where each customer gets agent inboxes, you’ll want a way to keep their mail apart.
7. Does it work where your agent lives? An MCP server lets chat-based agents like Claude and ChatGPT use the inbox directly. SDKs and framework toolkits matter for agents you build in code.

How CarlyEmail compares

This is our product, so read this section with that in mind. We built CarlyEmail for teams that need their agents to run whole email conversations, not just receive mail. Here’s how it lines up against what AgentEmail documents today:

AgentEmail’s free plan includes more email each month, and that’s worth saying plainly. Where CarlyEmail goes further is the rest of the conversation. Agents can send, reply, save drafts and label mail through the CarlyEmail API. Paid plans have no daily send cap, and new mail arrives as a signed webhook or over a WebSocket. People can connect it to Claude, ChatGPT, Perplexity or Grok as a custom connector. An agent can even sign itself up, and until the person it works for confirms, that account can only email its owner. If you cancel, your addresses and messages stay put on the free tier.

Who AgentEmail suits

AgentEmail is worth a look if:

• You’re prototyping an agent that mostly needs to receive mail, such as catching verification codes or reading invoices.
• You want the simplest possible API and a free plan with room to experiment.
• You’re comfortable working with a new vendor and confirming features directly.

Look elsewhere if:

• Your agent needs to send and reply through a documented API today.
• You need a security certification, an uptime commitment or a known team behind the service.
• You’re building for customers and need their mail kept separate.

Alongside CarlyEmail, AgentMail is the other established option, OpenMail keeps data in the EU, and Inkbox bundles an inbox with a phone number and iMessage under one agent identity. Our roundup of email MCP servers covers ways to give chat-based agents email access.

FAQ

Is AgentEmail the same as AgentMail?

No. AgentEmail (agentemail.co) and AgentMail (agentmail.to) are separate companies. AgentMail is a Y Combinator-backed company with a $6 million seed round. We found nothing linking the two.

Is AgentEmail free?

Yes, there’s a free plan with 3 inboxes and 3,000 emails a month. Paid plans start with Developer at $20 a month.

Can AgentEmail send emails?

Its homepage says agents can reply to email, but its public API reference only documents creating inboxes, reading threads and checking usage. Ask AgentEmail for the send and reply API before you rely on it.

Does AgentEmail support custom domains?

Its FAQ says yes, though the setup isn’t covered in the public docs. By default, inboxes use the @agentemail.co domain.

Does AgentEmail have an MCP server?

Its homepage lists “SDKs + MCP,” but we didn’t find MCP documentation on its site.

What’s a good alternative to AgentEmail?

CarlyEmail, which we make, and AgentMail are the main alternatives built for two-way agent email. Inkbox is an option if your agent also needs a phone number or iMessage.

Read https://docs.carlyemail.com/llms.txt and set yourself up with an email address.

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