Email sandbox simulator
Free Email Sandbox Simulator for API Testing
NoticeAPI includes an email sandbox simulator for developers who want repeatable tests before production. Use sandbox.noticeapi.com as the sender and simulator.noticeapi.com recipients to trigger delivered, bounced, complained, and suppressed outcomes.
curl -X POST https://www.noticeapi.com/api/v1/email/send \
-H "Authorization: Bearer ntc_xxxxxxxxxxxxxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
"from": "[email protected]",
"to": "[email protected]",
"subject": "Bounce test",
"text": "Watch the delivery timeline."
}'Real pipeline, fake mailbox
Simulator recipients record events and exercise webhook delivery without touching a real inbox.
CI-friendly addresses
Use delivered@, bounced@, complained@, and suppressed@ with optional +labels for deterministic test cases.
No reputation risk
Simulator sends do not use quota or sender reputation, and simulated bounces never suppress the simulator address.
Guardrails included
Simulator recipients cannot be mixed with real recipients in one send, so test traffic stays isolated.
How it works
From test send to production traffic.
Send from the sandbox domain
Use [email protected] while your production DNS is not configured.
Pick the simulator outcome
Address the message to delivered@, bounced@, complained@, or [email protected].
Assert the event trail
Fetch the email status endpoint or listen for webhook events to verify your integration handled the outcome.
Repeat without cleanup
Add +labels for unique test cases; simulated bounces stay repeatable and do not poison the address.
Trust
A safe testing path before production sending
The simulator is for product and CI tests, not inbox placement claims. It proves your API, logs, webhook, and suppression handling before you move to a verified production domain.
Implementation links
Build with the shipped docs.
FAQ
Questions developers ask before switching email.
Does the simulator send real email?
No. It records delivery events and webhook callbacks inside NoticeAPI, but no message is delivered to a real mailbox.
Can I mix simulator and real recipients?
No. The API returns mixed_simulation when simulator recipients and real recipients are in the same send. That keeps tests isolated.
Can I use it in automated tests?
Yes. Simulator addresses are deterministic and repeatable, making them useful for local development, CI smoke tests, and webhook handler tests.
Start free. Send production after your domain is ready.
Free includes 3,000 production emails per month, a 100/day production cap, and one verified sending domain.