MailingCore
DocumentationMonthly quota

Monthly quota

X-Quota headers, grace period, and blocking.

Each plan includes a maximum number of emails per month. Enforcement runs on every send (POST /emails/send, batch, campaigns).

Headers on each response

X-Quota-Limit: 5000
X-Quota-Used: 4100
X-Quota-Percentage: 82

If you are between 80% and 100%:

X-Quota-Warning: true

Enforcement levels

Limit usageBehavior
Below 80%Normal sending
80% – 100%Normal sending + X-Quota-Warning
100% – 110%Grace period — sending continues
Above 110%HTTP 429 — blocked until next cycle or upgrade

Plans (reference)

PlanEmails/month
Free100
Starter5,000
Pro25,000
Business100,000

Pricing and additional limits in Plans.

What to do at the limit

  1. Review usage in the dashboard or GET /billing/subscription
  2. Upgrade via POST /billing/checkout
  3. Wait for the monthly reset (after invoice.paid in Stripe)