Why mail might not arrive

Most of the ways a message fails to reach you here are silent by design. Nothing in the API reports them. That is deliberate: rejecting mail at SMTP would bounce every misdirected test message back at the sending provider and would answer address probes for anyone scanning the domain.

Work down this list in order. The first two cover almost every red test.

1. The sender is not authenticated — the limitation to know first

Cloudflare Email Routing rejects inbound mail that fails both SPF and DKIM, mail that fails the sending domain's DMARC policy, and mail from blocklisted IP addresses. This happens before our Worker runs, and it is not configurable by us or by you.

An unauthenticated development or staging SMTP server therefore disappears without a trace: no message, no error, and no log line either of us can read from the API.

Requirement. Test mail must come from a properly configured sender — Amazon SES, SendGrid, Postmark, or your own server with SPF, DKIM and DMARC in DNS. Verify this once, explicitly, before you rely on any assertion that a message did not arrive.

There is a second consequence of running a disposable-mail domain: the mail domain will end up on public disposable-email blocklists. That is inherent to the product. It does not affect this website or the API, but it does mean you cannot reliably use a @fabricatedemail.com address to sign up on a third-party site. Testing your own system under test is unaffected, and that is what the service is for.

2. No live subscription for the address

The mail is dropped silently. Expired, deleted and replaced subscriptions all look identical from the outside. Check that you registered the exact address, lowercased, on fabricatedemail.com — and not on api.fabricatedemail.com, which is the API, not the mail domain.

3. The account is over its monthly message cap

Free accounts store 60 messages per UTC calendar month, Pro accounts 25 000. Past the cap, mail is dropped silently for the rest of the month, for every address of the account. Nothing in the API says so.

What does say so: the dashboard shows both the number stored and the number dropped over the cap, and we email the account address at 80% and again at 100% of the cap. An upgrade raises the cap immediately but does not reset the count, and there is no reset other than the next month beginning.

Deduplicated repeats, mail for an address you never registered, and mail dropped by the 1 000-per-mailbox cap are not counted. A message stored headers-only is counted, because it was stored.

4. The account is suspended

Mail is dropped silently while an account is suspended, and every API request answers 403 {"error": "account suspended"}. Reinstatement restores everything as it was — except the mail that arrived meanwhile, which is gone.

Suspension is an operator decision, taken under the Acceptable Use Policy. Write to support if you believe it was a mistake.

5. The mailbox already holds 1 000 messages

Further mail to that one address is dropped silently. A test address that collects a thousand messages is almost always a local part that is not random enough, shared between jobs.

6. The message is larger than 25 MiB

Rejected by the mail platform at SMTP receipt, before the service sees it.

7. The subscription was deleted or replaced mid-delivery

If a subscription disappears while its mail is being stored, the message is dropped: the mailbox it was addressed to no longer exists.

8. A database failure during storage

Storage is best-effort to the extent the database is available; such a message may be lost. Re-running the test produces another one. The service claims no delivery guarantee stronger than that.

9. Retention

Mail is removed 24 hours after receipt on every tier, and mail belonging to an expired subscription goes with the subscription. Retention is not a tier feature and is not configurable — tests read their mail within seconds, and holding it longer would only enlarge what we store about other people.

When you still cannot explain it

Ask us to check the Workers logs and the zone's Email Routing activity log. Platform-edge rejections — case 1 — appear only in the second of those, which is why they are otherwise invisible. Log retention is three days, so write promptly: fabricatedemail-support@blackcurrantsecurity.com.

The service cannot send mail. A test that needs to send mail into a system under test uses its own provider.