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Email sending limits

Rate limits are enforced per organization and scale with your plan. Enterprise organizations are exempt from all email rate limits. Additionally, outbound send operations are subject to a burst limit:
  • Max 15 emails per 10 seconds per organization
  • Max 50 emails per 60 seconds per organization
Burst limits apply on all plans including Enterprise and cannot be exceeded regardless of tier.

Resource creation limits

Rate limit headers

Every API response includes rate limit headers so you can track consumption without polling:

SMS rate limits

SMS rate limits are enforced separately from API request rate limits. You can be within your email sending limits and still hit an SMS limit.
SMS limits are enforced at multiple levels: These limits reflect carrier constraints (Twilio Messaging Service) and apply regardless of plan tier. Exceeding any SMS limit returns 429 with error rate_limit_exceeded.

Handling 429 responses

When you receive a 429, inspect the Retry-After header and the retryAfter field in the response body. Both are in seconds.

Best practices

Queue high-volume sends. If you need to send more than a few hundred emails at once, queue them and dispatch at a controlled rate rather than hammering the API and hitting limits. Track remaining capacity. Read X-RateLimit-Remaining-Hour and X-RateLimit-Remaining-Day headers on each response. Slow down proactively when remaining drops below 10% rather than waiting for a 429. Separate SMS from email logic. SMS rate limiting is per-destination and per-phone-number. Structure your SMS dispatch so messages to the same recipient are spaced at least 1 second apart. Enterprise bypass. Enterprise organizations skip email send rate limiting entirely. If you are approaching the Business tier limits consistently, contact us to discuss Enterprise. Back to errors →
Last modified on March 19, 2026