An AgentMail alternative for your first agent inbox.
Give your agent an address on your own domain for $5/month. Robotomail brings email into OpenClaw, Hermes and Claude through MCP, with an API and CLI for the work you build around them.
Start free with a conversation to your own email address. Choose Solo when your agent needs to email other people.
Which one should you choose?
Choose Robotomail when you want one agent inbox on a custom domain at a small monthly cost, or prefer its MCP, REST and CLI setup. Solo is $5/month; Starter is $19/month and includes 10 mailboxes.
Choose AgentMail when its larger free allowance, multiple custom domains on Developer, or team features fit your project better. Its free plan has three inboxes; its $20 Developer plan includes ten custom domains.
Both services create inboxes for agents and support sending, receiving and threads. The useful differences are what your plan includes and how the service fits the way you run your agent.
Robotomail and AgentMail, side by side
| What your agent needs | Robotomail | AgentMail |
|---|---|---|
| Its own email address | Mailboxes on robotomail.co or a verified custom domain | API-managed inboxes and custom domains |
| Send, receive and reply | Message and thread APIs; attachments through the REST API | Messages, threads and attachments |
| Connect an existing agent | Remote MCP with browser approval; OpenClaw, Hermes and Claude setup guides | MCP and documented agent integrations |
| Build into your application | REST API, SDKs and CLI | API and SDKs |
| React to new messages | Webhooks, server-sent events (SSE), or message polling | Webhooks, WebSockets, or polling webhooks |
| Keep using an employee's Gmail account | Use the Gmail API for that requirement | Use a connected-account integration for that requirement |
Robotomail's MCP tools handle plain-text email; use the API for attachments, mailbox creation and domain management. Read the MCP tool reference and AgentMail's event documentation for the interface details.
What will your inboxes cost?
| Monthly plan | Robotomail | AgentMail |
|---|---|---|
| Free | 1 mailbox, 10 sends and 10 receives per month; test with your verified email address | 3 inboxes, 3,000 emails/month, 100 emails/day, 3 GB storage; no custom domain |
| One mailbox with your own domain | Solo: $5/month. 1 mailbox; 500 sends / month; 50 sends / day; 500 inbound / month; 1 custom domain; 1 GB storage | Developer: $20/month. Includes 10 inboxes and 10 custom domains |
| Several agent mailboxes | Starter: $19/month. 10 mailboxes; 15,000 sends / month per mailbox; 500 sends / day per mailbox; 2,000 inbound / month; 1 custom domain; 10 GB storage | Developer: $20/month. 10 inboxes, 10,000 emails/month, 10 custom domains, 10 GB storage |
Robotomail Free: 1 mailbox, 10 sends and 10 receives per month. Exchange mail only between your agent and your verified email address. Upgrade to email anyone. No credit card, no expiry. Allowances reset on the first of each month (UTC). Upgrade for higher limits or a custom domain.
Monthly list prices in USD, checked 3 November 2026. Annual discounts, taxes and optional add-ons are excluded. Robotomail lists sending and receiving allowances separately; AgentMail labels its allowance “emails/month”. Robotomail plans · AgentMail plans.
Three ways to compare the cost
One personal agent on your domain. Robotomail Solo is $5/month and includes 1 mailbox; 500 sends / month; 50 sends / day; 500 inbound / month; 1 custom domain; 1 GB storage. AgentMail's first plan with custom domains is Developer at $20/month, with more capacity included.
Several agents on one domain. Robotomail Starter is $19/month and includes 10 mailboxes; 15,000 sends / month per mailbox; 500 sends / day per mailbox; 2,000 inbound / month; 1 custom domain; 10 GB storage. AgentMail Developer is $20/month. The monthly list prices are $1 apart. Compare the integration and limits you need.
Several brands, each with its own domain. AgentMail Developer includes ten custom domains. Robotomail Starter includes 1 custom domain and Growth includes 5 custom domains. Compare the domain allowance and price with the number of brands you serve.
Sending bursts, storage and receiving volume still need to fit the selected plan. Compare Robotomail plans.
Try a real reply before moving your workflow
- Create your free account, verify your email and note your mailbox address.
- Open Connections, choose your agent and approve the connection. Start with OpenClaw, Hermes or Claude Code.
- From your verified email address, send the mailbox a short request. Ask the agent to read it and show you a reply.
- Approve the reply, then check that it arrives in the same conversation in your own inbox.
1 mailbox, 10 sends and 10 receives per month. Exchange mail only between your agent and your verified email address. Upgrade to email anyone. No credit card, no expiry. Allowances reset on the first of each month (UTC). Upgrade for higher limits or a custom domain. Upgrade when you are ready to email other people. If you are building your own application, follow the API quickstart.
Move one agent, then the rest
Start with a new Robotomail mailbox while your existing AgentMail workflow stays in place. Replace the API adapter or MCP connection for that one agent and map the mailbox and message identifiers your application stores.
Test one outgoing message, an incoming reply and a threaded response. Use the receive-and-reply guide for API payloads and reply headers. If the agent needs old conversations, keep access to that history or plan a separate import; creating a mailbox does not transfer it.
For your own domain, use a new subdomain for the first test or plan the MX change before switching incoming mail. Move one workflow at a time and disable the old sender when you switch.
What to check before a production rollout
Keep API keys in secret storage and scope them to the mailbox when appropriate. For MCP, review the permissions on the browser approval screen. Your application or agent runtime decides which actions need approval.
Test webhook signatures, duplicate events and recovery after a disconnect. Check actual delivery with your own domain and recipients. For contractual requirements such as an SLA, processing location or audit reports, confirm the required plan with the vendor.
See Robotomail's security guide. Product details and public prices were reviewed on 3 November 2026; this comparison is written by Robotomail.
Common questions
For one mailbox with a custom domain, Robotomail Solo is $5/month; AgentMail Developer is $20/month and includes more inboxes and domains. For a free prototype, AgentMail offers a larger allowance. Compare the workload and features you need.
Continue building
Start with one mailbox. Build the workflow you need.
Create a mailboxChoose a mailbox, connect your agent, then test a conversation.