DEV Community: DevNPlay

How to Automate OTP Extraction and Email Testing in n8n with Disposable Inboxes

DevNPlay — Mon, 27 Apr 2026 16:06:54 +0000

If you've ever tried to automate signup flows or OTP-based authentication testing in n8n, you've probably hit the same wall — there's no clean way to receive emails as a workflow trigger without setting up your own mail server or polling an IMAP node that drops events under load.

I ran into this exact problem while building OpenInbox, a disposable email API. So I built an n8n community node for it.

Here's what it does and how to use it.

The problem with IMAP polling in n8n

n8n's built-in email trigger uses IMAP polling. That means it checks your inbox on an interval — every 60 seconds by default. For automated testing workflows this is painful:

You get delays between email arrival and workflow execution
Under load, events get dropped or queued unpredictably
You can't create isolated inboxes per test run — you're sharing one inbox

What the OpenInbox node does differently

The n8n-nodes-openinbox node uses a webhook trigger. The moment an email lands in your disposable inbox, OpenInbox fires a webhook to n8n — no polling, no delays, no dropped events.

You also get:

Create inboxes on the fly — spin up a fresh inbox inside any workflow
Full raw email payload — subject, body (plain + HTML), sender, headers, attachments
Write your own parser logic — use n8n's built-in Code node or Regex node to extract exactly what you need
Custom domain support — use your own domain for the disposable addresses
Delete messages after processing to keep things clean

Install it (no approval needed for self-hosted)

The node is published to npm and installable right now on any self-hosted n8n instance:

Settings → Community Nodes → Install → type:

n8n-nodes-openinbox

Restart n8n and the node appears in your editor. That's it.

Note: The node is pending official n8n verification for cloud users. Self-hosted users (Docker, VPS, Railway, etc.) can install it immediately.

Workflow example: OTP extraction automation

Here's a real workflow you can build in under 5 minutes.

Use case: You want to automate testing of an email-based OTP signup flow.

Nodes:

OpenInbox — Create Inbox → creates a fresh disposable address (e.g. test-abc123@openinbox.io)
HTTP Request → triggers your signup form with that address
OpenInbox — Email Trigger (Webhook) → fires the moment the OTP email arrives
Code node → extracts the OTP from the raw email body

// Example Code node — extract 6-digit OTP from email body
const body = $json.body_plain;
const match = body.match(/\b\d{6}\b/);
return [{ otp: match ? match[0] : null }];

Continue your workflow with the extracted OTP — submit a form, validate a token, log results, whatever you need.

No regex guessing at polling intervals. No shared inbox contamination between test runs. The webhook fires and your workflow continues in real time.

Other use cases

CI/CD email validation — spin up a unique inbox per test run, send a transactional email through your system, assert on subject line, content, sender, and delivery time. Tear it down when done.

QA signup flow testing — test your entire onboarding email sequence in isolation without touching production inboxes or real user addresses.

Email-triggered pipelines — use a disposable address as a lightweight inbound webhook alternative. Anything that can send an email can now trigger an n8n workflow.

I was manually checking a competitor's website every day. So I built something to stop doing that

DevNPlay — Thu, 16 Apr 2026 19:40:33 +0000

I was manually checking a competitor's website every day. So I built something to stop doing that.

This is a little embarrassing to admit.

For months, I had a tab pinned in my browser. A competitor's pricing page.
I'd open it every couple of days, stare at it, try to remember what it
looked like last time, and close it.

No system. No alerts. Just vibes and a bad memory.

Then I missed something. They quietly changed their pricing for a week —
a promotion I only found out about after it ended. By the time I noticed,
the window was closed.

That was enough. I decided to stop doing this manually.

I looked for a tool. Nothing felt right.

The options I found were either:

Overkill enterprise tools with pricing to match
Abandoned projects that hadn't been touched in years
Too technical to set up without writing scripts

I didn't want to write scripts. I just wanted something to watch a URL
and tell me when it changed.

So I built it myself.

Introducing ChangePulse

ChangePulse monitors any public webpage and
alerts you the moment something changes.

You paste a URL. Pick how often to check it. Choose how you want to be
notified — email, Slack, or webhook. That's it. ChangePulse handles
everything else and sends you an alert with a visual diff showing exactly
what changed and what was there before.

No scripts. No server. No manual refreshing.

The use cases surprised me

I built this to solve my own competitor monitoring problem. But since
launching I've heard from people using it for things I didn't anticipate:

Watching company career pages to catch job postings the moment they go live
Tracking supplier and vendor pages for price or stock changes
Monitoring government and regulatory pages for policy updates
Keeping an eye on a product page waiting for a restock
Agencies monitoring competitor pages for their clients as a value-add

The common thread: people who need to know when something changes, but
don't want to babysit a browser tab to find out.

It's free to start

There's a free plan with 5 monitors and daily checks. No credit card,
no commitment.

If you've ever found yourself manually refreshing a page waiting for
something to change — this was built for exactly that moment.

Try ChangePulse for free → changepulse.io

What websites do you find yourself checking manually that you wish you
could automate? Curious what use cases I haven't thought of yet.

I Built a Disposable Email API for Developers

DevNPlay — Wed, 04 Mar 2026 00:12:31 +0000

I Built a Disposable Email API for Developers

As a developer, I constantly run into the same problem while testing apps:

I need email addresses for verification emails.

Whether it's:

testing signup flows

password reset emails

QA automation

bot testing

CI pipelines

Using my personal inbox quickly becomes messy with dozens of test emails.

So I built OpenInbox — a disposable email service designed for both developers and regular users.

👉 https://openinbox.io

Why I Built It

Many temporary email websites already exist, but they usually have a few problems:

slow email delivery

overloaded with intrusive ads

no developer APIs

unreliable inboxes

I wanted something that was:

fast

simple

API-friendly

So OpenInbox was born.

What OpenInbox Does

OpenInbox lets you instantly create temporary inboxes and receive emails without signing up.

You can use it directly from the browser or through the API.

Common use cases include:

testing signup verification emails

automation scripts

QA testing

protecting your real email from spam

temporary registrations

Looking for Feedback

I’m continuously improving OpenInbox and adding new features like:

browser extensions

more API capabilities

automation tools

If you're a developer who needs disposable emails for testing, feel free to try it.

👉 https://openinbox.io

I’d love to hear your feedback or suggestions.

DEV Community: DevNPlay

How to Automate OTP Extraction and Email Testing in n8n with Disposable Inboxes

The problem with IMAP polling in n8n

What the OpenInbox node does differently

Install it (no approval needed for self-hosted)

Workflow example: OTP extraction automation

Other use cases

Links

I was manually checking a competitor's website every day. So I built something to stop doing that

I was manually checking a competitor's website every day. So I built something to stop doing that.

I looked for a tool. Nothing felt right.

Introducing ChangePulse

The use cases surprised me

It's free to start

I Built a Disposable Email API for Developers