> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.usglobalmail.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.usglobalmail.com/_mcp/server.

# Rate limited

Returned as `application/problem+json` with `code` `rate_limited` and HTTP status `429`.

You have made too many requests in the current window.

The response includes a `Retry-After` header telling you how long to wait.

## Common causes

* Request volume exceeded the limit for your API key.

## How to resolve

* Wait for the `Retry-After` interval (seconds), then retry.
* Back off on repeated 429s — the official SDKs do this automatically.

## Example

```json
{
  "type": "https://docs.usglobalmail.com/api/problems/rate_limited",
  "title": "Rate limit exceeded.",
  "status": 429,
  "code": "rate_limited",
  "request_id": "req_8f3c2a1b9d",
  "instance": "/v1/mails"
}
```

> **Note**
>
> This error is typically transient — safe to retry with exponential backoff.

See also: [Rate limits](/guides/core-concepts/rate-limits).