Rate Limits

Mailjet applies rate limits to API requests. When a limit is reached, the API returns 429 Too Many Requests.

Mailjet does not publish rate-limit figures. Build your integration to handle 429 responses with a retry mechanism rather than relying on a fixed request rate.

When a request returns 429, we recommend the following:

• Wait before retrying the affected request. Do not retry immediately in a tight loop.
• Use exponential backoff. Increase the delay after each consecutive 429 response, up to a maximum delay appropriate for your application.
• Add jitter. Add a random variation to the delay so that multiple clients do not all retry at the same time.
• Limit retry attempts. If the request continues to receive 429 responses after your retry limit is reached, log the failure and surface it through your application's error handling or monitoring.

Limit concurrent requests and spread out bursts of API calls. Use bulk operations where supported to perform more actions in a single request, including transactional sending and contact management.