Checker

Fake email signups quietly wreck your numbers: inflated user counts, abused free trials, and a database full of addresses that bounce. Checker is an API that screens every new signup against a continuously updated list of 170,000+ disposable domains and rejects the junk before it ever becomes a row in your records.

What Checker actually does

It sits between your signup form and your database, checks each address in real time, and hands back a verdict you can act on. The core capabilities:

• Screen signups against a database of 170,000+ disposable domains
• Block trial hoarders and multi-account users before they register
• Cut wasted server load from fake accounts and spam signups
• Connect through the API for real-time checks across any workflow
• Drop in the WordPress plugin for protection without custom code
• Track activity live through a real-time analytics dashboard
• Maintain custom blacklists and whitelists for the edge cases

Two things stand out beyond the domain list. The real-time dashboard lets you watch fake-signup attempts as they happen rather than discovering them in a monthly cleanup, and the per-second request limits scale with how much traffic you actually push through the API. Neither needs babysitting once it is wired in, which is the point of a screening layer that lives in the background.

Who it's built for

If you run a free trial or a freemium tier, you already know the cost of fake accounts: support tickets from abusers, skewed conversion data, and storage you pay for but never monetize. Checker earns its place fastest for SaaS founders and indie developers whose trial limits keep getting gamed by people spinning up throwaway inboxes. The WordPress plugin widens that net to membership and course sites, which get the same screening without a developer touching the API. The honest counterpoint: if your product gates by credit card rather than email, or your signups are low-volume and hand-reviewed, a disposable-domain filter solves a problem you may not actually have.

The deal

Tier 1 starts at $9 and covers unlimited disposable email checks, 2 API keys, a request limit of 3 per second, and the WordPress plugin. Tier 2 at $19 raises that to 5 requests per second, and Tier 3 at $29 reaches 10 requests per second with an extra platform slot. For a tool that runs in the background and keeps your user table clean, the entry price is hard to argue with. [Grab the Checker deal on DealMirror](https://www.grabltd.com/recommends/checker-dm/).