How to stop temp mail Sign ups on your website

mail-check.tech

Hey everyone 👋
Haven’t posted in a while because I’ve been working on something super exciting with my friend and today, we’re finally sharing it with the world:
Say hello to MailCheck.

🎯 The Problem

Let’s be honest — we’ve all, at some point, used disposable email services like temp-mail.org to get that extra free trial or bypass an email wall. While it may seem harmless from a user’s point of view, it’s a real headache for companies.

Free trial abuse, spam sign-ups, and inflated user metrics — these aren’t just minor inconveniences. For businesses, they mean:

Wasted server resources and API usageSkewed analytics and user engagement dataExtra customer support costsReduced trust in the platform

We realized just how widespread this issue is when we were personally exploiting it. That’s when the light bulb went off.
What if we could build a tool that prevents disposable emails before they even hit your backend?

🚀 Introducing MailCheck

MailCheck is an API service that lets you verify email addresses in real time — and detect whether they’re legit, or just a disposable inbox waiting to be forgotten.

It goes way beyond basic syntax validation. We use a combination of:

Domain analysisMX record checksBehavior trackingA constantly updated list of disposable email providers

The goal? Help you catch fake or throwaway signups — without slowing down your users’ experience.

🛠️ How MailCheck Works

📌 Base URL

All requests are sent to:

https://api.mail-check.tech

🔐 Authentication

Every request must include your API key:

X-API-Key: your_api_key_here

⚡ Verification Methods

We provide two levels of verification depending on your need for speed vs certainty.

1. S1 Verification (Standard)

Checks domain analysis, MX records, usage patternsCompares against our list of known disposable email providersFast and perfect for sign-up forms

Sample Request (S1)

curl -X POST https://api.mail-check.tech/api/v0/validate/email
-H “Content-Type: application/json”
-H “X-API-Key: your_api_key_here”
-d ‘{“email”: “user@example.com”}’

Sample Response

{
“is_valid”: true,
“needs_TBA”: false,
“reason”: “Domain has valid MX records and passes all verification checks”
}

2. TBA Verification (Task-Based Authentication)

Includes everything from S1Adds behavior-based analysisIdeal for higher-risk or suspicious emails

Sample Request (TBA)

curl -X POST https://api.mail-check.tech/api/v0/validate/email/tba
-H “Content-Type: application/json”
-H “X-API-Key: your_api_key_here”
-d ‘{“email”: “user@example.com”}’

Sample Response

{
“is_valid”: true,
“needs_TBA”: false,
“reason”: “Email passed Task-Based Authentication verification”
}

🧠 Recommended Workflow

1. Use S1 verification for every sign-up
2. If `is_valid = true` and `needs_TBA = false`, you’re good ✅
3. If `is_valid = false`, reject the email ❌
4. If `needs_TBA = true`, call the TBA endpoint for deeper verification 🔍

Note: IF needs_TBA is false you shouldn’t perform it since it’s time consuming,
and effective for cases when S1 checks return needs_TBA as true.

🧯 Error Handling

Here’s a sample error you might get if your API key is missing:

{
“detail”: “API key missing. Please provide a valid API key in the X-API-Key header.”
}

Common HTTP errors include:

401 — Unauthorized403 — Forbidden422 — Malformed request429 — Rate limited500 — Internal error

Thanks for reading! If you found this helpful or know someone who runs a platform dealing with fake sign-ups — feel free to share 💬

and for any query related mail-check.tech contact product@mail-check.tech

How to stop temp mail Sign ups on your website was originally published in Coinmonks on Medium, where people are continuing the conversation by highlighting and responding to this story.