u/eu-m

If you’re running a SaaS, you’ve probably dealt with people using disposable emails to create multiple accounts, abuse free trials, or just spam your platform. It looks small at first, but over time it messes with your metrics, costs you money, and clutters your system.

Instead of maintaining huge lists or relying on paid APIs, I built a lightweight check that blocks most of these temp emails instantly. It’s fast, cheap, and works before the signup even goes through.

It’s free and open source,

npm install tempmail-checker

A really solid first layer of defense against churners and fake users.

If you’re running a SaaS, you’ve probably dealt with people using disposable emails to create multiple accounts, abuse free trials, or just spam your platform. It looks small at first, but over time it messes with your metrics, costs you money, and clutters your system.

Instead of maintaining huge lists or relying on paid APIs, I built a lightweight check that blocks most of these temp emails instantly. It’s fast, cheap, and works before the signup even goes through.

It’s free and open source,

npm install tempmail-checker

A really solid first layer of defense against churners and fake users.

I couldn’t find a disposable email checker that was both fast and hard to bypass, so I made one called tempmail-checker.

npm install tempmail-checker

Instead of just relying on a static list, it uses a Bloom filter with a HashSet fallback. That keeps lookups basically instant while still staying accurate. It catches subdomain tricks, which a lot of simple lists miss.

The blocklist auto-updates and currently has 5300+ domains. The Bloom filter handles most checks on its own, so it stays lightweight and fast.

Been testing it in real use cases like signup validation and spam prevention, and it’s holding up well so far.

If you’ve dealt with edge cases or bypass tricks, I’d like to hear them.

If you’re running a SaaS, you’ve probably dealt with people using disposable emails to create multiple accounts, abuse free trials, or just spam your platform. It looks small at first, but over time it messes with your metrics, costs you money, and clutters your system.

Instead of maintaining huge lists or relying on paid APIs, I built a lightweight check that blocks most of these temp emails instantly. It’s fast, cheap, and works before the signup even goes through.

It’s free and open source,

npm install tempmail-checker

A really solid first layer of defense against churners and fake users.

If you’re running a SaaS, you’ve probably dealt with people using disposable emails to create multiple accounts, abuse free trials, or just spam your platform. It looks small at first, but over time it messes with your metrics, costs you money, and clutters your system.

Instead of maintaining huge lists or relying on paid APIs, I built a lightweight check that blocks most of these temp emails instantly. It’s fast, cheap, and works before the signup even goes through.

It’s free and open source,

npm install tempmail-checker

A really solid first layer of defense against churners and fake users.

If you’re running a SaaS, you’ve probably dealt with people using disposable emails to create multiple accounts, abuse free trials, or just spam your platform. It looks small at first, but over time it messes with your metrics, costs you money, and clutters your system.

Instead of maintaining huge lists or relying on paid APIs, I built a lightweight check that blocks most of these temp emails instantly. It’s fast, cheap, and works before the signup even goes through.

It’s free and open source,

npm install tempmail-checker

A really solid first layer of defense against churners and fake users.