The response headers describe your current rate limit following every request in conformance with the sixth IETF standard draft:
Header nameDescription
ratelimit-limitMaximum number of requests allowed within a window.
ratelimit-remainingHow many requests you have left within the current window.
ratelimit-resetHow many seconds until the limits are reset.
retry-afterHow many seconds you should wait before making a follow-up request.

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Default Rate Limits

The default maximum rate limit is 2 requests per second across all API endpoints. This applies uniformly to:
  • Email sending endpoints: 2 requests per second
  • Email management endpoints: 2 requests per second
  • Domain/configuration endpoints: 2 requests per second
  • All other API endpoints: 2 requests per second
This number can be increased for trusted senders upon request.

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Rate Limit Response

After exceeding the rate limit, you’ll receive a 429 Too Many Requests response error code: 
{
  "error": "Rate limit exceeded",
  "message": "Maximum 2 requests per second allowed. Upgrade or contact support for higher limits."
}

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Increasing Rate Limits

If you have specific requirements that exceed the default limits, you can request a rate increase:
1

Contact Support

Reach out to our support team at support@inbound.new with your requirements.
2

Provide Use Case Details

Include details about your use case, expected volume, and business requirements.
3

Review and Approval

Our team will review your request and work with you to find an appropriate solution.

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Rate Limit by Endpoint

Rate limits are applied per API key. If you’re using multiple API keys, each key has its own rate limit bucket.
Important: The SDK will return rate limit errors directly - you must handle them in your application code.

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Next Steps

Authentication

Learn how to authenticate your API requests

Send Your First Email

Start sending emails with proper rate limiting

Error Codes

See all API error codes including rate limit responses