Sending

Send test emails

Simulate delivered, bounced, complained, and suppressed events with MailBlastr test addresses — without harming your domain reputation.

While building your integration it is important to exercise the different deliverability outcomes — a delivery, a hard bounce, a spam complaint, a suppressed recipient. MailBlastr provides reserved test addresses that trigger each event reliably, so you can verify your webhooks, event handling, and suppression logic without mailing real people.

Do not test by inventing fake addresses or pointing at a throwaway SMTP server — both can hurt your domain reputation. Use the addresses below instead.

Test sends still count against your account’s sending quota and produce real email objects with a full event log.

Available test addresses

Address	Simulates
`delivered@mailblastr.dev`	A successful delivery — the email advances to `delivered`.
`bounced@mailblastr.dev`	A hard bounce (an SMTP `550 5.1.1` "Unknown User"). The email moves to `bounced` and the recipient is auto-suppressed.
`complained@mailblastr.dev`	The message is delivered but the recipient marks it as spam — a `complained` event, and the recipient is suppressed.
`suppressed@mailblastr.dev`	The recipient is already on your suppression list, so the send is skipped with status `suppressed`.

Send to a test address

import { MailBlastr } from 'mailblastr';

const mb = new MailBlastr('mb_xxxxxxxxx');

const { data, error } = await mb.emails.send({
  "from": "Acme <hello@yourdomain.com>",
  "to": ["bounced@mailblastr.dev"],
  "subject": "Testing a bounce",
  "html": "<p>This should hard-bounce.</p>"
});
console.log({ data, error });

Labeling test runs

The delivered, bounced, and complained addresses support plus-labeling: add any string after a + (e.g. delivered+signup@mailblastr.dev) and the event still fires, but the recipient address now identifies that specific test run. This is useful for correlating webhook callbacks back to the flow that triggered them.

delivered+signup@mailblastr.dev
delivered+password-reset@mailblastr.dev
bounced+import-batch@mailblastr.dev

The suppressed@mailblastr.dev address does not support labeling.