Once Email official documentation · v1

Account and billing

Account and billing: Authoritative product and developer guidance for receiving temporary email, troubleshooting delivery, and testing authorized email flows safely.

Reviewed 15 August 2026

What you can do

Account and billing: Authoritative product and developer guidance for receiving temporary email, troubleshooting delivery, and testing authorized email flows safely. API Key secrets appear once at creation or rotation; the service stores only an irreversible digest and non-sensitive prefix. Verify the current page version and follow the linked next step; never infer a capability from a screenshot, old article, or package name.

Failures and recovery

Account and billing: Authoritative product and developer guidance for receiving temporary email, troubleshooting delivery, and testing authorized email flows safely. Stripe Test Mode is not Live billing. Checkout remains unavailable while the production billing flag is off. Verify the current page version and follow the linked next step; never infer a capability from a screenshot, old article, or package name.

Security and limits

Account and billing: Authoritative product and developer guidance for receiving temporary email, troubleshooting delivery, and testing authorized email flows safely. Subscription, failed payment, cancellation, refund, and entitlement changes require signed webhook and ownership verification. Verify the current page version and follow the linked next step; never infer a capability from a screenshot, old article, or package name.