Hey Product Hunt!

A traditional anti-spam strategy has always been Double Opt-In (sending an activation link to the user s inbox). However, many modern disposable email services give users a temporary inbox instantly allowing them to click verification links in seconds while still using a fake identity.

This leaves builders stuck choosing between adding heavy CAPTCHAs (which ruin conversion rates) or letting burner emails through.

What is your strategy?

Hey developers of Product Hunt!

As software engineers, nothing is worse than an API that takes hours to set up due to messy docs, complex auth flows, or high latency response times.

When building MailCheck API, our goal was simple:

1. Keep average response time under 50ms.

2. Zero complex dependencies a simple REST call with instant JSON feedback.

3. Drop-in snippets for Node, Python, Dart/Flutter, and cURL.

Hey PH community!

When building sign-up and authentication flows, every extra 100ms of latency can lower conversion rates. However, skipping validation checks leaves your platform wide open to bot registrations and disposable email abuse.

When we built MailCheck API, our primary engineering focus was keeping response times under 50ms at the edge so security checks wouldn't impact the onboarding experience.

Questions for the devs here:

Hey everyone!

Temporary email services like 10MinuteMail and TempMail are evolving fast. Burner domain providers constantly rotate their top-level domains (TLDs) and use custom MX record configurations to bypass standard domain blocklists.

While compiling and maintaining our dataset of 40+ million blocked domains, we noticed a huge surge in temporary emails using non-standard TLDs specifically to bypass basic regex filters on SaaS signup forms.

Curious to hear from founders and product leads:

Hey Product Hunt!

After seeing multiple SaaS platforms waste server resources and proxy bandwidth on fake accounts, I decided to build MailCheck API a high-performance microservice designed to stop trial abuse right at the signup door.

Building high-availability infrastructure with sub-50ms latency as an independent builder came with some great technical challenges.

Ask Me Anything about:

Hey Product Hunt Community!

While building developer tools, one recurring issue I kept seeing across various SaaS platforms especially those offering free trials was trial abuse driven by temporary/disposable email addresses (like 10minutemail, etc.).

Users create unlimited disposable accounts, hogging backend resources, proxy bandwidth, and database storage without ever intending to upgrade.

To solve this, we built MailCheck API a lightweight, 50ms email validation microservice designed to instantly filter out burner emails at signup before they hit your DB.

Hey PH Community!

When running a SaaS platform with a free tier or trial, inactive "junk" users created with burner emails do more than just waste server resources:

• They distort your actual user acquisition & churn metrics.

• They cost money in automated welcome email campaigns & proxy traffic.

• They ruin your email domain sender reputation when welcome emails bounce.

We built MailCheck API as a 50ms gateway to stop burner accounts right at the signup form before they ever touch your primary database.