IsTempMail is a disposable email detection service that provides a simple JSON API and a WordPress plugin to block temporary email addresses used for spam, fake registrations, and free trial abuse.
What is IsTempMail?
IsTempMail is a real-time disposable email detection service. It accepts an email address or domain as input via a single check API endpoint and returns a JSON response indicating whether the domain is a known disposable email provider and if it is unresolvable. The service also offers a free WordPress plugin and API libraries for JavaScript (npm) and PHP (GitHub). It was created by the team behind FastCron.
Key Features
- Huge database – Over 124,000 domains of known disposable email providers, with 6286 entries added in the last four weeks.
- Simple JSON API – One endpoint: POST an email or domain to
https://istempmail.com/api/check/{API_TOKEN}/{domain}. Returns name, blocked (boolean), and optionally unresolvable.
- WordPress integration – Plugin “Block Temporary Email” available on WordPress.org; install, sign up for a free API token, and enter the token in WP Admin.
- Always up-to-date – Between 5 and 20 new temporary email domains added daily via automated and manual processes.
- Developer-friendly – Source-available PHP and JavaScript libraries; direct access to an engineer on paid plans.
- Fair pricing – Free plan includes 200 requests per month; paid plans start at $5/month for 5,000 requests (Standard), $10/month for 15,000 (Plus), $20/month for 50,000 (Pro), and $50/month for unlimited (Max). Non-profit discounts available – Contact by email.
Who should use IsTempMail?
- WordPress site owners – Block disposable emails during user registration and comments using the free WordPress plugin.
- SaaS and subscription businesses – Prevent free trial abuse and fake signups by validating email addresses at registration via the API.
- Developers – Integrate the JSON API into any application using the provided libraries or raw POST requests using API Documentation.
Use cases
- Validate user signups in real time – On form submission, send the email address to the API and reject disposable addresses before account creation.
- Clean existing user lists – Batch check email domains against the API to identify and remove temporary email users.
- Report new disposable domains – Users with an account can report domains via the report page; others can email Contact by email.
How does IsTempMail work?
- Sign up for a free API token.
- Send a POST request to the
check endpoint with your API token and the domain or email address to validate.
- Receive a JSON response with
blocked: true or false and an optional unresolvable flag.
- For WordPress, install the plugin, enter your API token in the admin settings, and it will automatically block disposable email registrations and comments.
Pricing
IsTempMail offers a free plan (200 requests per month) and four paid tiers: Standard ($5/month, 5,000 requests), Plus ($10/month, 15,000 requests), Pro ($20/month, 50,000 requests), and Max ($50/month, unlimited requests). No credit card required to start. Non-profit discounts are available – Contact by email.
FAQ
