Runearc vs AgentMail
Both give agents their own inboxes over an API and MCP. AgentMail is further along; Runearc adds sending for apps, a support inbox and custom domains on the free plan.
Updated 4 min read
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In short
AgentMail is the product that made “inboxes for agents” a category. It is a good product: an API, Python and Node SDKs, MCP, IMAP and SMTP, webhooks and websockets, pods for multi tenant apps. Runearc covers the same ground for agents and goes wider: custom domains on the free plan, sending for apps from any verified address, and a shared support inbox for people.
Pick AgentMail if
- You want official Python or Node SDKs today.
- You need a SOC 2 report, an EU region or white labelling (Startup and Enterprise plans).
- You want features Runearc does not have yet, such as drafts or a calendar per inbox.
Pick Runearc if
- You want your own domain on the free plan.
- Your agent should wait for a code in one call, with codes and links already extracted.
- The same product should also send your app's email and run support@ for people.
Who each is for
AgentMail describes itself as email inboxes for AI agents [6]. Its free plan gives 3 inboxes and 3,000 emails a month; custom domains start on the $20 Developer plan [1]. Pods and scoped keys serve platforms that give each of their own customers an inbox [4].
Runearc is for agents and the apps around them. Each workspace gets a private {code}.runearc.email domain where any address works through a Catch-all, so an agent can make up a new address per task without creating anything first. Projects, roles and inbox scoping cover teams; sending keys and SMTP cover app email.
Features and prices
Runearc is currently free. The paid Runearc prices below are planned and come from our pricing page; billing is not live yet.
Swipe sideways to see the AgentMail column.
| Feature | Runearc | AgentMail |
|---|---|---|
| Free plan | 3 inboxes, 3,000 emails a month, 3 custom domains | 3 inboxes, 3,000 emails a month, 100 a day, no custom domains [1] |
| First paid plan | Pro, $9 a month: 25 inboxes, 50,000 emails, 10 domains | Developer, $20 a month: 10 inboxes, 10,000 emails, 10 domains [1] |
| Next plan | Scale, $99 a month: 250 inboxes, 250,000 emails, unlimited domains | Startup, $200 a month: 150 inboxes, 150 domains [1] |
| Instant addresses without DNS | Any address on your private runearc.email code, with a Catch-all | Not stated |
| Wait for an email, codes and links extracted | Yes: wait in the API, CLI and MCP | No dedicated endpoint documented; OTP sign ups are a listed use case |
| MCP server | Remote (API key) and stdio | Remote with OAuth or API key, plus a stdio bridge [2] |
| SDKs | A Node and edge SDK, coming to npm; REST, CLI and MCP | Python and Node [5] |
| IMAP and SMTP | Yes, with app passwords per inbox | Yes [3] |
| Events | Standard Webhooks and a WebSocket | Webhooks and websockets [1] |
| Multi tenant | Projects, workspace and project roles, inbox scoped keys | Pods and scoped keys [4] |
| Sending for apps from any verified address | Yes: POST /v1/emails and SMTP | Sends from inboxes |
| Shared support inbox for people | Yes: assign, close, snooze, keyboard shortcuts | Not stated |
| Compliance and regions | Not yet | SOC 2 report on Startup; EU region on Enterprise [1] |
Sources, read on October 14, 2026
- [1]AgentMail pricing: www.agentmail.to/pricing
- [2]AgentMail, MCP: docs.agentmail.to/integrations/mcp
- [3]AgentMail, IMAP and SMTP: docs.agentmail.to/imap-smtp
- [4]AgentMail, multi tenancy: docs.agentmail.to/multi-tenancy
- [5]AgentMail, API reference: docs.agentmail.to/api-reference
- [6]AgentMail home page: www.agentmail.to
Prices change. If something here is out of date or wrong, email hello@runearc.com and we will fix it.
Where AgentMail is better
- It is further along. AgentMail is a paid product with SDKs, a SOC 2 report and enterprise options. Runearc is newer and currently limits access.
- SDKs. Typed Python and Node clients are nicer than raw HTTP. Runearc has neither yet.
- Breadth of agent features. AgentMail documents drafts, a calendar per inbox, reply extraction and allow and block lists. Runearc does not have drafts or calendars.
Where Runearc is better
- Your domain, free. Add up to 3 custom domains on the free plan. If DNS is on Vercel or Cloudflare, Runearc writes the records for you; elsewhere it checks each record live.
- Fewer calls for sign ups. One blocking call returns the email with
codesandlinkspulled out. No polling loop, no parsing. See the design notes. - Addresses cost nothing.
run-4812@k7m3qz.runearc.emailworks the moment you think of it, and the Catch-all does not count against your inbox limit. - One product for the whole company's email. The agent's inbox, the app's password reset emails and support@ live in the same project, under the same keys and roles.
- Price. The planned Pro plan is $9 a month for 25 inboxes and 50,000 emails.
Moving from AgentMail
The concepts map closely, so most of a move is renaming calls. There is no import tool; old mail stays where it is.
- Inboxes:
POST /v1/inboxeswith alocal_part, or skip creation entirely and use the Catch-all with a fresh address per run. - Pods: create a project per tenant, or one project with an inbox key per agent, so a key can reach one inbox and nothing else.
- Webhooks: Runearc signs with Standard Webhooks (
webhook-id,webhook-timestamp,webhook-signature). Re-register your URL and update the verification step. - MCP: swap the server URL in your client config. See give an MCP agent its own email.
curl https://api.runearc.com/v1/inboxes \
-H "Authorization: Bearer $MAILBAY_API_KEY" \
-H "Content-Type: application/json" \
-d '{"local_part": "signup"}'
curl "https://api.runearc.com/v1/inboxes/ibx_.../wait?timeout=60" \
-H "Authorization: Bearer $MAILBAY_API_KEY"
# {"message": {...}, "codes": ["482913"], "links": ["https://example.com/verify?token=..."]}Read next
- An email inbox for your AI agentAn agent that signs up for things needs an address that receives mail, and a way to get the code out of it without polling. Here is the whole flow in three steps.
- Runearc vs OpenMailOpenMail and Runearc both start from the same idea: an agent should have its own inbox. They differ on custom domains, policy controls and what else sits in the product.
- Giving AI agents an email address: design notesAn agent is not a person with a mail client. It cannot glance at an inbox or click around. These are the decisions we made so an agent can use email in as few steps as possible.
Put Runearc to work
Get inboxes, sending, your own domains and MCP in one workspace. The free plan includes 3 inboxes, 3,000 emails a month and 3 custom domains, with no card.