Email Verification in an n8n Workflow

The shape of the workflow

Any automation that signs up for something on your behalf hits the same wall: a code arrives by email and the workflow has no inbox to read. The fix is to create the address inside the workflow, so the run owns it end to end.

1. Create inbox — HTTP Request, POST, returns the address as plain text
2. Do the thing — whatever your workflow already did, using that address
3. List messages — HTTP Request, GET, returns everything on the account
4. If — did a message for this address arrive yet?
5. Wait — 5 seconds on the false branch, then back to step 3
6. Extract — pull the code or link out of the message body

Credentials

Register once, then create a Header Auth credential in n8n rather than pasting the key into each node. Name it something like EmptyInbox API and reuse it across every HTTP Request node in the workflow.

curl -X POST https://emptyinbox.me/api/auth/register \
  -H "Content-Type: application/json" \
  -d '{"username": "n8n-automation"}'

# {"api_key": "ei...", "inbox_quota": 5}

In the credential, set the header name to Authorization and the value to Bearer ei... with your key.

Node 1: create the inbox

Method POST, URL https://emptyinbox.me/api/inbox, your Header Auth credential, and response format set to String. That last setting matters: the endpoint returns the address as plain text, and leaving the format on JSON makes the node fail on a body that is not JSON.

Reference the result downstream as {{ $json.data.trim() }}, or whatever field name you gave the string output.

Nodes 3 to 5: the polling loop

The list endpoint returns every message on the account, so filter to the address this run created.

// If node, condition (JavaScript expression)
{{ $json.some(m => m.inbox === $('Create inbox').item.json.data.trim()) }}

True branch continues to extraction. False branch goes to a Wait node set to 5 seconds, whose output connects back to the List messages node. That backward connection is the loop.

Give the loop a ceiling. n8n will happily cycle forever if the mail never arrives, so either cap the workflow with an execution timeout or keep a counter in static data and fail the run past a threshold.

Node 6: extract the code

A Set node with an expression is usually enough. For a six digit code:

{{ $json.find(m => m.inbox === $('Create inbox').item.json.data.trim())
     .text_body.match(/\b\d{6}\b/)[0] }}

For a confirmation link, match on a URL pattern instead and feed the result into an HTTP Request node that visits it. Messages also carry html_body, subject, sender and timestamp if you need to assert on more than the body text.

Cost of a scheduled workflow

One inbox credit is consumed per inbox created, not per message received. A workflow that runs hourly and creates one inbox per run spends about 720 credits a month, which is roughly $38 at bulk rates. If the runs do not each need a fresh identity, create one inbox and reuse the address across runs, which costs a single credit.

Messages are deleted after 7 days, so a long-lived reused inbox does not accumulate storage.

Frequently asked questions