If you're collecting emails for signups, leads, or trials — you're probably losing money to throwaway addresses.

Here's the reality: services like Guerrilla Mail, Temp Mail, and Mailinator let anyone create a fake email in seconds. They sign up for your free trial, abuse your service, and vanish.

The cost is real:

• Inflated user counts that wreck your metrics

• Wasted onboarding emails (hello, bounced sends)

• Abused free trials that eat into your margins

• Support tickets from accounts that never convert

What actually works:

1. Validate at the gate. Check every email at signup against a disposable email database. Block or flag them before they hit your system.

1. Use an API, not a static list. New throwaway domains appear daily. Static blocklists go stale within weeks. You need a live detection API that updates continuously.

1. Don't just block — redirect. Instead of a hard rejection, prompt users to use a real email. Some people use temp emails out of habit, not malice.

I built Pyzit's Temp Mail Detector API to solve exactly this. It checks against thousands of disposable domains in real-time and updates daily.

Beyond that, we've put together a full toolkit for business owners who code — invoice generators, SEO tools, code editors, file converters — all the stuff you'd otherwise be duct-taping together from 10 different sites.

If you're building a SaaS, running a startup, or managing any product with user signups — this stuff matters more than most people realize.