One address, or ten thousand.
Programmable, privacy-first email built for individuals, AI agents, automation, and large-scale device fleets.
The same product at every point on the curve.
There are no separate editions. Moving from one address to a fleet is a plan change and some extra pairing.
1address
An individual with one private address.
10devices
A developer or a small team, pairing what they already own.
100devices
An operations team running tagged, searchable devices in bulk.
1,000+devices
A fleet operator provisioning email addresses across a whole deployment.
A private email address, simply.
Create an account, create an email address, read your mail. Add a device later if you want one.
- No sign-up form, email address or password. An account is twelve words your device generates. The first unlock on a new device takes about 40 seconds.
- Mail is sealed to a key only your devices hold before it is stored. Remote content is never fetched, so nothing reports back to the sender.
- Retention is a setting: 24 hours, 7 days, 30 or 90 days, after which mail is deleted.
- Read it on your phone, your laptop, or both. The same inbox wherever you are signed in.
You can ignore the rest of this page. Devices, tags and bulk operations appear once you pair something.
An inbox for your agent, sealed on arrival.
Give an AI agent its own email address through MCP. It waits for mail, reads it and replies, and decrypts on the machine it runs on.
- Pair an agent with one command and a line pasted into the app. The key its address keys are sealed with never passes through us.
- Seven MCP tools: wait for a message, read it, open its attachments, reply, send, list messages and list addresses. Replies and new mail can carry files. Works with Claude and any other MCP client.
- Every agent starts reply-only: it can answer whoever wrote to it and no one else. You can let it send to anyone, up to 20 messages an hour (more on Fleet and Enterprise), or turn sending off.
- Message bodies reach the model marked as the sender's words, so instructions hidden in mail read as information.
- Agents send from the addresses you give them, on a shared domain or one you bring, within your plan's daily limit.
On Scale and above. The model provider your agent uses sees what the agent reads, so choose one you would trust with that mail.
Programmable email infrastructure that fits into your application.
Mailcycle's own console is built on the same HTTP API you can call. Mint an address, attach it to a device, read what arrives.
- Create an email address programmatically, and delete it when you are done to free its place on your plan.
- List, rename, tag, disable and revoke devices, and send mail from your own addresses, over the same surface. Sending from a paired device is on Personal and above, and with an API key on Scale and above.
- Read mail for one address or across every address a device holds.
- Identifiers are opaque and prefixed, errors carry stable machine-readable codes, timestamps are ISO 8601 UTC.
- API keys for scripts, on Operator and up, so a script does not have to run the recovery-phrase handshake. They have no expiry date.
- Webhooks from Operator: mail arriving, devices pairing and addresses changing, POSTed to your URL, signed and retried. The same events over a WebSocket for code that is connected. Events carry ids, never content.
- SDKs for TypeScript, Python, Go, Rust, Swift, PHP, Java, .NET and Ruby that do the encryption on your machine: create addresses that receive mail, wait for a message, read it and its attachments, reply, send, and listen to the event stream. The encryption format is published, so a client in any language can be written against it.
Message content comes back sealed. Your client decrypts it with a key derived from the recovery phrase, which the SDK does for you. There is no server-side search.
Addresses for systems that need to receive something.
Sign-in codes, verification links, delivery receipts, alerts: many automated processes need a real email address. Mailcycle gives each one its own.
- Mint email addresses on demand and delete each one when the process is finished with it, freeing its place on your plan.
- Give a test environment its own addresses without attaching them to anyone's personal mailbox.
- Assign several addresses to one Worker when a single runner handles many flows (Personal and above).
- Keep the whole estate visible in one account, with every address and your plan limit on the same screen.
From Personal up, a device can send from the addresses assigned to it, and on Scale and above an AI agent can answer the mail it receives. Free receives mail only.
Centrally manage email identities across devices and workflows.
One Operator account holds the devices, the addresses and the assignments between them. "Which device is receiving that?" is answered on one screen.
- Tag devices by team, environment, location or anything else you filter by later (Operator and above).
- Read the mail for any address on the account remotely, without physically holding the device.
- Remove one device without disturbing the rest. Each device has its own credential.
- Plan, address limit and payment in one place, with downgrades checked against the addresses you hold before they apply.
- Share addresses with the people who work them (Fleet and above). Each has their own account and reads with keys sealed to it; give each address as read-only or read and send, and take it back at any time.
Mailcycle knows who is in a team and which addresses each person holds, as it must to serve them. It never holds a key to the mail.
From one device to thousands.
Provision email addresses across your fleet and manage them from one Operator account. Devices are unlimited on every paid plan; you pay for the addresses you hold.
- Connect devices in seconds with a QR code, or an 8-digit code where there is no camera.
- Devices need no user accounts. A Worker holds a credential, not an identity.
- Search, filter and sort the device list, select many devices, and disable, enable or remove them in one action (Operator and above).
- Distribute addresses however the deployment needs them, and move them between devices by unassigning and reassigning. A device that is open picks up the change at once.
One platform. Every inbox. Every device.
Start with the email address you need today. The same account scales to a fleet later.