Rate Limiting

Mail.td applies rate limits to ensure fair usage and service stability.

Limits

Layer	Rate Limit	Keyed by	Applies to
Public endpoints	8 req/s	IP	Domain list, login, registration
Free (authenticated)	8 req/s	IP	Email operations (/api/accounts/{id}/*)
Pro (authenticated)	20 req/s	IP	Same endpoints, higher limit
Account creation (free)	1 per 8s	IP	POST /api/accounts without Pro token
Account creation (Pro)	8 req/s	IP	POST /api/accounts with Pro token

Rate Limit Response

When you exceed the limit, the API returns 429 Too Many Requests:

{
  "error": "rate_limit_exceeded"
}

Best Practices

• Use WebSocket for real-time updates instead of polling GET /api/accounts/{id}/messages repeatedly
• Cache domain lists — available domains rarely change
• Use exponential backoff when retrying after a 429
• Batch operations where possible — don't create/delete accounts in tight loops

Example: Retry with Backoff

async function fetchWithRetry(url, options, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    const res = await fetch(url, options);
    if (res.status !== 429) return res;

    const delay = Math.pow(2, i) * 1000; // 1s, 2s, 4s
    await new Promise(r => setTimeout(r, delay));
  }
  throw new Error('Rate limit exceeded after retries');
}