SES: Maximum sending rate exceeded Email / SMTP Origin: Network Last updated 4 Nov 2026

Amazon SES: Throttling — Maximum sending rate exceeded (454 Throttling failure)

You are sending faster than your Amazon SES account's per-second limit, so SES throttles the requests.

Exact message you may see Maximum sending rate exceeded454 Throttling failure: Maximum sending rate exceededThrottling Maximum sending rate exceeded SESDaily message quota exceeded SESThrottling: Maximum sending rate exceeded
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Seen on: SMTP AWS

Meaning

SES enforces a maximum send rate (messages per second) and a 24-hour quota that depend on your account's sending limits. Slow your sender, add a rate limiter with retries and exponential backoff, or request a limit increase. New accounts start in the sandbox with very low limits.

Common causes

  • Loop sending without delay
  • Parallel workers exceeding the per-second rate
  • Account still in sandbox with low limits
  • 24-hour quota exhausted
  • Burst after a queue backlog

⚡ Quick fix

  1. Add a rate limiter at or below MaxSendRate
  2. Retry with exponential backoff on Throttling / 454
  3. Request a sending-limit increase or move out of the sandbox

Detailed fix by platform

AWS CLI

  1. aws sesv2 get-account --query '{Sandbox:ProductionAccessEnabled,Limits:SendQuota}' shows the max send rate and 24-hour quota

How to diagnose

  1. Rate — Send rate vs MaxSendRate?
  2. Quota — 24-hour usage?
  3. Mode — Sandbox or production?

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

Where this error sits

Origin: Network. Errors that are often confused with or caused by this one (click to open):

421 4.7.0 Try again later (rate limited) — SMTP: 421 4.7.0 Our system has detected an unusual rate of unsolicited mail originating from your IP address. Mail sent from your IP address has been temporarily rate limited (Email / SMTP)421 4.7.0 Try again l…429 Too Many Requests (Laravel throttle) — Laravel: Illuminate\Http\Exceptions\ThrottleRequestsException: Too Many Attempts. / 429 Too Many Requests (Laravel)429 Too Many Requests…450 4.7.1 Greylisted, please try again later — SMTP: 450 4.7.1 <user@example.com>: Recipient address rejected: Greylisted, see http://postgrey.schweikert.ch/help/example.com.html (Email / SMTP)450 4.7.1 Greylisted,…452 4.5.3 Too many recipients — SMTP: 452 4.5.3 Your message has too many recipients / 452 Too many recipients received this hour (Email / SMTP)452 4.5.3 Too many re…550 5.4.5 Daily user sending quota exceeded — SMTP: 550 5.4.5 Daily user sending quota exceeded (Gmail) (Email / SMTP)550 5.4.5 Daily user …Mailgun: Sandbox domains are for test purposes only — Mailgun: 403 Forbidden — Sandbox subdomains are for test purposes only. Please add your own domain or add the address to authorized recipients (Email / SMTP)Mailgun: Sandbox doma…MessageRejected — SES MessageRejected: Email address is not verified. The following identities failed the check in region (AWS)MessageRejectedSendGrid 403: from address does not match a verified Sender Identity — SendGrid: 403 Forbidden — The from address does not match a verified Sender Identity. Mail cannot be sent until this error is resolved (Email / SMTP)SendGrid 403: from ad…SES: Maxi…

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