Terms of Service
Last updated: May 18, 2026
By using Mailsnail you agree to these terms. They're written to be short and unambiguous. If anything is unclear, email hello@mailsnail.dev and we'll clarify before you continue.
1. The service
Mailsnail is an MCP server and HTTP API that prints and mails physical letters and postcards via USPS on your behalf. You (or an AI agent acting under your account) compose the content; we handle production and delivery.
2. Your account
- You must be 18 or older to use the service.
- You are responsible for everything sent through your account, including everything sent by AI agents you authorize.
- Keep your API keys secret. If a key leaks, rotate it immediately.
3. Acceptable content
You may not use the service to send mail that:
- Threatens, harasses, defames, or impersonates another person.
- Violates US federal, state, or postal law (this includes but isn't limited to USPS Domestic Mail Manual rules on non-mailable matter).
- Contains content that infringes someone else's intellectual property.
- Promotes fraud, illegal goods, or misleading commercial offers.
- Targets recipients for unsolicited bulk mail without lawful basis.
We run automated moderation on every piece before printing. We reserve the right to refuse or hold any piece that appears to violate this policy and to suspend accounts that abuse the service.
4. Payment
- The sandbox is free. Production mail is pay-per-piece, charged when the piece is accepted for printing.
- We may change prices with 30 days' notice. Existing queued mail is not affected by the change.
- Payments are processed by a third-party processor and are non-refundable once a piece has been printed.
5. Delivery
Once a piece is handed to USPS, delivery is governed by USPS. We'll surface tracking events when available, but we're not liable for delays or losses caused by the carrier.
6. Your content
You retain ownership of everything you send. You grant us a limited license to print, fold, address, and post each piece — and to retain the contents for 90 days for support and audit per the privacy policy.
7. Service availability
We aim for high availability but make no uptime guarantee. We may perform maintenance that temporarily affects the service.
8. Liability
The service is provided “as is.” Our maximum aggregate liability for any claim is the amount you paid us in the 12 months before the claim. We aren't liable for indirect, incidental, or consequential damages.
9. Termination
You can close your account any time. We can suspend or terminate accounts that violate these terms, with or without notice depending on severity.
10. Changes
We'll update this page when these terms change. Continuing to use the service after a change means you accept the new terms.