Terms of Service

Effective October 15, 2026.

These terms are the agreement between you and the operator of MachineMail ("MachineMail", "we", "us") for using MachineMail: machinemail.dev, the dashboard, the API, the MCP server, the CLI and the docs (together, "the service").

By creating an account, creating an API key, or letting an agent use the service, you agree to these terms. If you use MachineMail for a company, you agree for that company and confirm you can bind it; "you" then means the company. Our Privacy Policy explains how we handle data.

01 The service

MachineMail gives AI agents their own email addresses. You can create inboxes on our shared domain (machinemail.dev) or on your own domains, send and receive mail through the API, the CLI or MCP, and get events through webhooks, streams and MCP Events. Every inbound message gets a trust report.

We change and improve the service often. We may add, change or remove features. If we remove something you rely on in a paid plan, we will tell you in advance where we reasonably can.

02 Your account

• You must be at least 18 years old and able to form a binding contract.
• Give us a real email address, and keep it working: we send sign-in codes and important notices there.
• Keep your API keys, sessions and OAuth grants secret. Anything done with them counts as done by you. If one leaks, revoke it and tell us.
• You are responsible for the people you invite to your organization and the roles you give them.

03 Your agents

MachineMail is built for software that acts on its own. That does not move responsibility to us or to the agent.

• You are responsible for what your agents do with MachineMail, as if you did it yourself: every message they send, every reply, every action they take because of mail they read.
• Agents act with the access you grant. That includes apps such as ChatGPT and Claude that you connect through OAuth or an API key. You can revoke any grant or key at any time in the dashboard.
• Self-registered agents. An agent can register itself through auth.md and get a sandbox inbox before a person is involved. When you claim an agent, it joins your organization and these terms cover it from then on, including what it did before.
• The trust layer helps, but it is not a guarantee. It flags phishing and prompt injection and withholds quarantined mail from agents. It will sometimes miss bad mail and sometimes flag good mail. Build your agents so a single email can't make them do something harmful: check the trust level before acting, and keep a person in the loop for anything that matters.

04 Acceptable use

You and your agents must follow our Acceptable Use Policy, which is part of these terms. It sets out what MachineMail may be used for, the content and conduct that are banned (including spam, purchased or scraped lists, phishing, malware, mass sign-ups and getting around our limits), the rules for agents, and the sending standards your mail has to meet.

Also, don't resell the service, or use it to build a competing product by copying it, without our written permission.

Inbox names on our shared domain are first come, first served. Some names are reserved, including role addresses (such as postmaster) and well-known brand names. We may take back a shared-domain address that impersonates someone or is used for abuse.

05 Sending limits and enforcement

We protect the reputation of our domains and of every customer's mail. Today:

• An unclaimed agent gets one sandbox inbox, which lasts 24 hours, and can send only a small number of messages to a small number of recipients from it. The limits in force are shown on the limits page.
• Agent registration, sign-in and claim attempts are rate limited.
• An organization can hold up to 1,000 inboxes on the shared domain. There is no cap on the number of inboxes on your own verified domains. Sending limits still apply.
• An address that bounces permanently or reports your mail as spam goes on your suppression list. We refuse further sends to it.

We may change these limits, and set others, to keep the service healthy. Current limits are in the docs.

If we believe you or your agents are breaking these terms, we may, without notice where the abuse is serious:

• suspend sending: your inboxes still receive mail, and you can still read, export and get webhooks;
• suspend your organization: reads, exports and inbound mail still work, but changes are refused;
• remove content, or revoke keys and grants involved in the abuse;
• close your account (see Termination).

We tell you why where we can. To appeal, email support@machinemail.dev.

06 Plans, the free tier and billing

• Free tier. The free plan's features are on our pricing page. Inbound and outbound mail both count as messages. Spam and quarantined mail don't count.
• Paid plans. Paid plans are monthly subscriptions that renew automatically until you cancel. You can cancel at any time; cancelling takes effect at the end of the current billing period.
• Overage. Usage beyond what your plan includes is billed in arrears: at the end of each monthly billing period, we charge for that period's usage at the rates on the pricing page.
• Plan changes. An upgrade takes effect immediately, and the price difference for the rest of the current billing period is charged pro rata. A downgrade takes effect at the end of the current billing period; until then you keep your current plan.
• Who sells and bills. Paid plans are sold through Polar (polar.sh), which acts as Merchant of Record and authorized reseller. Polar takes the payment, issues invoices and receipts, and collects and pays sales tax and VAT. When you buy a paid plan you also agree to Polar's Buyer Terms, which govern the purchase itself.
• Taxes. Prices on the pricing page don't include taxes. Polar adds any sales tax or VAT that applies, based on your billing address, at checkout.
• Refunds. Fees for billing periods that have started are non-refundable, and we don't pro-rate refunds for unused time or for a downgrade or cancellation partway through a billing period, unless the law requires otherwise or the service wasn't provided. Polar processes any refund. Your rights under Polar's Buyer Terms, including chargebacks, are not affected. To ask about a charge, email support@machinemail.dev.
• Price changes. We will give you 30 days' notice before a price change affects you.
• Non-payment. If a payment fails and isn't fixed within 14 days, we may move you to the free plan or suspend sending.

07 Your content

Your content is the mail, attachments, drafts and other data you and your agents put into MachineMail or receive through it. You own it.

You give us permission to host, copy, process, transmit and display your content only as needed to run the service for you. That includes the trust layer's automated analysis and the providers listed in the Privacy Policy. We don't use your content for anything else.

You are responsible for your content, and for having the right to send, receive and process it. A data processing agreement (DPA) is available on request: email support@machinemail.dev.

08 Other services

Your agents may work with services we don't control: AI apps such as ChatGPT and Claude, your DNS provider, your webhook endpoints, and the mail servers on the other end. Their terms govern your use of them. We are not responsible for them.

We deliver mail through email providers. Email delivery is never guaranteed: the receiving side decides whether to accept, filter or reject a message.

09 Feedback

If you send us ideas or suggestions, we may use them without owing you anything.

10 Availability

We work to keep MachineMail fast and available, but we don't promise it will be uninterrupted or error-free. There is no service level agreement (SLA) for any plan, including Scale, unless we sign one with you.

11 Termination

• You can stop using MachineMail at any time. Delete your inboxes in the dashboard or the API, or email support@machinemail.dev to delete your organization. Export anything you want to keep first: we delete your organization within 30 days of your request.
• We can suspend or close your account if you break these terms, if your use puts the service, other customers or third parties at risk, if you don't pay, or if the law requires it. Where it is reasonable, we will warn you first and give you time to export your mail.
• If we close your account, you have 30 days to export your data, unless we closed the account for serious abuse or the law prevents it. Then we delete it, as described in the Privacy Policy.

The sections on your content, disclaimers, liability and indemnity continue after the agreement ends.

12 Disclaimers

The service is provided "as is" and "as available". To the extent the law allows, we disclaim all warranties, express or implied, including merchantability, fitness for a particular purpose and non-infringement.

In particular, we don't warrant that the trust layer will catch every phishing message or prompt injection, that it will never flag legitimate mail, or that any message will be delivered.

13 Limitation of liability

To the extent the law allows:

• Neither party is liable to the other for indirect, incidental, special, consequential or punitive damages, or for lost profits, revenue or data, even if told they were possible.
• Our total liability for all claims about the service is limited to the greater of the amounts paid for MachineMail (including through Polar) in the 12 months before the claim and US$100.

Some places don't allow these limits, so they may not all apply to you.

14 Indemnity

To the extent the law allows, you will indemnify us (and anyone who operates MachineMail) against claims, damages and costs (including reasonable legal fees) that come from your content, from what your agents do, from your breach of these terms, or from your breach of the law.

15 Changes to these terms

We may update these terms. We will post the new version here and update the effective date. If a change is material, we will email account owners 30 days before it takes effect. If you keep using MachineMail after that, you accept the new terms. The same notice applies to material changes to the Acceptable Use Policy, except that we may change that policy with immediate effect to address abuse or a legal requirement.

16 General

• These terms, the Acceptable Use Policy, the Privacy Policy and any order or agreement we sign with you are the whole agreement between us about the service.
• If part of these terms can't be enforced, the rest still applies.
• Not enforcing a right is not giving it up.
• You may not transfer these terms without our consent. We may transfer them as part of a merger, acquisition or sale of assets, or to a company formed to operate MachineMail.
• Neither party is liable for delays caused by events beyond its reasonable control.

17 Contact

Email support@machinemail.dev.