Temp Email Checker
Free Disposable Email Detector & Burner Email Lookup Tool
Use our free temp email checker to instantly check disposable email domains and block burner email signups. This online throwaway email checker cross-references a database of 200+ known DEA (disposable email address) providers, performs MX record verification, detects catch-all domains, checks SPF and DMARC authentication, and assigns a weighted risk score. Use the bulk mode to clean your entire user list at once. Perfect for bot signup protection, trial-period abuse prevention, and CRM data hygiene.
Quick Answer: What Is a Temp Email Checker?
A temp email checker is a disposable email detector that identifies whether an email domain belongs to a throwaway or burner service. Our fake email address finder checks against 200+ known DEA providers (Mailinator, Guerrillamail, Yopmail, etc.), verifies MX records, performs SMTP handshake testing for catch-all domain detection, checks SPF and DMARC records, and assigns a risk score from 0 to 100. It correctly distinguishes privacy providers (Proton Mail, Tuta) from actual disposable services — essential for real-time form validation, referral fraud detection, and sender reputation protection.
Check If an Email Domain Is Disposable
Enter a domain or email address to detect disposable email providers and assess risk.
Jessica Wright
Cybersecurity Threat Researcher
Jessica specializes in email fraud prevention, disposable email detection, IP blacklist analysis, DMARC/SPF authentication, and anti-abuse systems. She helps SaaS platforms, e-commerce stores, and email marketers protect signup forms, clean CRM data, and maintain sender reputation.
View All Articles by Jessica WrightWhat Is a Temp Email Checker and How Does It Detect Disposable Emails?
A temp email checker is a disposable email detector that identifies whether an email domain belongs to a temporary, throwaway, or burner email service. According to Wikipedia's article on disposable email addresses, DEAs are temporary email identities that self-destruct after a short period — usually 10 minutes to 24 hours. Services like Mailinator, Guerrillamail, Yopmail, and 10MinuteMail provide these addresses so users can bypass email verification without revealing their real identity.
Our online throwaway email checker uses a multi-layered detection approach that goes far beyond a simple domain list. It cross-references your input against a curated database of 200+ known DEA (disposable email address) providers, performs MX record verification to check if the domain can actually receive mail, tests for catch-all domains via SMTP handshake, and verifies SPF and DMARC authentication records. The result is a weighted risk score from 0 to 100 with a clear verdict: Trusted, Privacy, Corporate, Suspicious, or Disposable.
Whether you are protecting a SaaS signup form from trial-period abuse, cleaning your CRM before a campaign, or implementing real-time form validation, this fake email address finder gives you the intelligence you need to block fraudulent signups at the gate.
Key Fact: Our temp email checker database covers 200+ disposable providers. It also correctly identifies privacy providers like Proton Mail and Tuta as legitimate services — not disposable — because privacy and disposability are fundamentally different concepts.
How to Block Disposable Emails on Your Signup Form in 2026
Blocking disposable email signups is essential for maintaining clean user data and preventing free-tier exploitation. Here is how to implement bot signup protection using our temp email checker methodology.
Server-Side Domain Validation
The most reliable method is server-side validation. When a user submits a signup form, extract the domain portion of their email address and check it against a disposable domain database. Our tool maintains a list of 200+ providers that gets regularly updated. Combine this with MX record verification to catch domains with no mail server — a clear sign of an invalid or abandoned domain.
Real-Time Form Validation for SaaS
For real-time form validation, implement an AJAX call that checks the domain as the user types. Display a warning message when a disposable domain is detected: "Please use a permanent email address to complete registration." This approach works perfectly for Shopify, WooCommerce, and custom SaaS platforms. For additional user verification, cross-reference the signup IP with our IP Fraud Score Checker to detect repeat offenders using VPNs.
Catch-All Domain Blocking
Catch-all domains accept email for ANY username — whether the mailbox exists or not. Disposable services use catch-all configurations because they generate random addresses on the fly. While some legitimate businesses use catch-all, combining it with other disposable indicators (new domain, no SPF, no DMARC) creates a strong fraud signal. Verify your own email authentication setup with our Email Verifier.
# PHP Example: Block disposable emails at signup
$email = $_POST['email'];
$domain = substr(strrchr($email, "@"), 1);
# Check against disposable domain list
$disposable_list = file('disposable-domains.txt', FILE_IGNORE_NEW_LINES);
if (in_array(strtolower($domain), $disposable_list)) {
$error = "Disposable emails are not allowed. Please use a permanent address.";
}
# Also verify MX records exist
if (!getmxrr($domain, $mx_hosts)) {
$error = "This email domain has no mail server.";
}
Catch-All Domains: What They Are and Why They Matter for Fraud Detection
A catch-all domain is configured to accept email for any address at that domain, regardless of whether the specific mailbox actually exists. If you send an email to randomstring12345@example.com and the server accepts it, that domain is likely a catch-all. Our DEA validator detects this through SMTP handshake testing.
How Catch-All Detection Works
Our tool connects to the domain's primary MX server on port 25 and performs an SMTP handshake. It sends a RCPT TO command with a random, non-existent email address. If the server responds with a 250 (OK) code, the domain is a catch-all. If it responds with 550 (User Not Found), the domain validates individual mailboxes — a sign of legitimate infrastructure. A 450/451 response indicates greylisting, which legitimate servers use as an anti-spam measure.
Why Catch-All Matters for Fraud
Disposable email services almost always use catch-all configurations because they need to accept mail for any randomly generated address. However, some legitimate enterprises also use catch-all for backup purposes. The key is combining catch-all detection with other signals: a domain that is catch-all AND in the disposable database AND has no SPF record is almost certainly a burner. A corporate domain that is catch-all but has SPF, DMARC, and established MX records is likely legitimate. Check domain registration age with our WHOIS Lookup for additional context.
Important: Never block catch-all domains alone. Many legitimate businesses (including Fortune 500 companies) use catch-all configurations. Always combine catch-all detection with disposable database matching and authentication record checks for accurate classification.
How to Prevent Trial Hopping with Temporary Email Detection
Trial hopping (also called trial farming) occurs when users create multiple accounts with different disposable emails to abuse free trial periods indefinitely. This is one of the most common forms of free-tier exploitation affecting SaaS platforms, streaming services, and cloud tools.
The Trial Hopping Attack Chain
A single user creates an account with user1@mailinator.com, uses the 14-day free trial, then creates another account with user2@guerrillamail.com for another trial. With 200+ disposable providers offering unlimited addresses, one person can generate thousands of accounts. This inflates your signup metrics, wastes server resources, and prevents legitimate conversion.
Multi-Layer Defense Strategy
- Layer 1 — Domain Check: Use our temp email checker to block known disposable domains at signup.
- Layer 2 — Catch-All Detection: Flag catch-all domains that generate unlimited addresses.
- Layer 3 — Email Confirmation: Require a confirmation link click to activate the trial.
- Layer 4 — IP Fraud Score: Cross-reference the signup IP with our IP Fraud Score Checker to detect VPN/proxy usage common in trial farming.
- Layer 5 — Browser Fingerprinting: Use our Browser Info Tool to identify repeat signups from the same device even with different emails and IPs.
Why Are My Marketing Emails Going to Spam? Email Deliverability in 2026
If your marketing emails are landing in spam, the root cause is often a damaged sender reputation. One of the biggest contributors is sending to disposable and invalid email addresses that generate hard bounces. Our email deliverability checker approach helps you clean your list before sending.
Gmail and Yahoo 2024-2026 Sender Guidelines
Google and Yahoo now require all bulk senders to authenticate with SPF, DKIM, and a published DMARC policy. Senders with bounce rates above 2% risk being throttled or blocked entirely. Our tool checks SPF and DMARC records for any domain, helping you verify both your own authentication and your subscribers' domain quality.
How Disposable Emails Destroy Sender Reputation
When you send to a disposable address that has already self-destructed, the mail server returns a hard bounce. High bounce rates signal to ISPs that you are not maintaining your list, which lowers your domain reputation and IP reputation. Even a 5% bounce rate can trigger spam filtering. Use our IP Blacklist Checker to verify your sending IP is not already flagged. Also read our guide on checking IP reputation for bulk email marketing.
Spam Traps and Honeypots
Spam traps are email addresses specifically designed to catch senders with poor list hygiene. Pristine spam traps have never been used by real users. Recycled spam traps are abandoned addresses that ISPs reactivate as traps. Hitting a spam trap instantly damages your reputation. Our temp email checker helps identify domains that are likely to contain or become spam traps.
How to Remove Disposable and Temporary Emails from Your Email List
Cleaning your email list is essential for CRM data hygiene and maintaining high deliverability. Our bulk temp email checker lets you audit up to 25 domains at once. Here is the complete workflow.
10-Step Email List Cleaning Workflow
- Step 1: Export your email list from Mailchimp, Shopify, HubSpot, or your ESP as CSV.
- Step 2: Extract the domain portion from each email address (everything after the @ symbol).
- Step 3: Paste unique domains into our bulk disposable email domain checker (up to 25 at a time).
- Step 4: Remove all domains flagged as Disposable (risk score 70+).
- Step 5: Remove domains with no MX records (cannot receive email).
- Step 6: Flag catch-all domains for manual review.
- Step 7: Verify remaining emails individually with our Email Verifier for SMTP-level validation.
- Step 8: Check your sending IP against blacklists using our IP Blacklist Checker.
- Step 9: Verify your own SPF, DKIM, and DMARC configuration with our DNS Lookup Tool.
- Step 10: Re-verify quarterly — new disposable providers appear constantly.
Best Practice for Shopify and Mailchimp Users: Run this audit before every campaign. Even a small percentage of disposable addresses can damage your sender reputation. Our best email validator for Shopify and Mailchimp users catches addresses that passed initial signup validation but use domains that have since become known disposable providers.
Privacy Providers vs Disposable Services: Understanding the Difference
A critical distinction that many disposable email detectors get wrong is the difference between privacy-focused email providers and actual disposable services. Our tool correctly classifies these categories.
Privacy Providers (Legitimate — Low Risk)
Proton Mail, Tuta (formerly Tutanota), Mailfence, Hushmail, and StartMail are privacy email providers — not disposable services. They offer permanent, encrypted mailboxes with strong privacy protections. Users of these services have real, persistent accounts. Blocking them alienates privacy-conscious customers and may violate GDPR principles. Our tool classifies these as "Privacy" with a low risk score of 15.
Disposable Services (Temporary — High Risk)
Mailinator, Guerrillamail, 10MinuteMail, Yopmail, and similar services provide temporary, self-destructing email addresses that expire within minutes to hours. Users of these services are deliberately avoiding identification. These get a risk score of 90-95 and a "Disposable" verdict. Our burner email lookup tool maintains an updated database of 200+ such providers.
The Gray Area: Hosting Providers
Email addresses hosted on GoDaddy, Bluehost, or OVH infrastructure are neither disposable nor major providers. They typically belong to small businesses or personal domains. Our tool classifies these as "Hosting" with a moderate risk score. For deeper domain intelligence, use our WHOIS Lookup to check registration age and registrar details.
Referral Fraud Detection: How Disposable Emails Enable Abuse
Referral programs that reward users for inviting friends are a prime target for abuse via disposable emails. A single person can create dozens of fake referral accounts using burner email addresses, earning rewards without bringing genuine users.
The Referral Fraud Pattern
The attacker signs up with their real email to get a referral link, then creates 50 fake accounts using different disposable domains (mailinator.com, guerrillamail.com, etc.) — each "referred" by their link. Each fake signup triggers a referral reward. The fake accounts never convert, never engage, and eventually bounce when you try to email them.
How to Stop Referral Fraud
Integrate our temp email checker into your referral validation flow. Block disposable domains from being eligible for referral rewards. Require email confirmation before crediting referrals. Cross-check the referring IP against our IP Fraud Score to detect mass signups from the same source. Monitor for patterns like multiple signups from the same browser fingerprint — use our Browser Info Tool for fingerprint data.
For a comprehensive overview of how signup fraud works at the network level, read our guide on understanding IP reputation scores.
Free API to Check for Burner Email Addresses: Integration Guide
For developers building user onboarding security systems, here is how to implement disposable email detection programmatically using the same approach our temp email checker uses.
Building a Fraud Prevention API
# Node.js Example: Check disposable email via DNS + database
const dns = require('dns');
const disposableList = require('./disposable-domains.json');
async function checkEmail(email) {
const domain = email.split('@')[1].toLowerCase();
// Check 1: Disposable database
const isDisposable = disposableList.includes(domain);
// Check 2: MX records exist
const hasMX = await new Promise(r => dns.resolveMx(domain, (e,a) => r(!e && a.length > 0)));
// Check 3: SPF record
const hasSPF = await new Promise(r => dns.resolveTxt(domain, (e,a) =>
r(!e && a.flat().some(t => t.startsWith('v=spf1')))));
return { domain, isDisposable, hasMX, hasSPF };
}
This approach gives you a fraud prevention API that works server-side without external dependencies. For enhanced detection, add our catch-all SMTP test and DMARC verification. Protect your API endpoints with proper authentication — generate strong API keys using our Password Generator. Secure your API with SSL — verify certificates with our SSL Checker.
Complete Disposable Email Detection Audit Checklist
Use this comprehensive checklist with our temp email checker to protect your platform from fake signups and maintain clean user data.
- Step 1: Check the signup domain against our 200+ disposable email database using the burner email lookup tool.
- Step 2: Verify MX records exist — domains without mail servers cannot receive confirmation emails.
- Step 3: Test for catch-all domains via SMTP handshake to detect accept-all configurations.
- Step 4: Check SPF and DMARC records — legitimate domains almost always have authentication.
- Step 5: Verify the email address itself with our Email Verifier for SMTP-level validation.
- Step 6: Check the signup IP fraud score with our IP Fraud Checker.
- Step 7: Look up domain registration age via our WHOIS Lookup — newly registered domains are higher risk.
- Step 8: Verify your own sending domain's DNS with our DNS Lookup Tool.
- Step 9: Check your mail server IP against blacklists with our IP Blacklist Checker.
- Step 10: Review server security headers on your signup page with our HTTP Headers Analyzer.
Pro Tip: Run the full audit weekly for high-traffic platforms. New disposable providers appear daily, and existing ones frequently change domain names to evade detection. Read our detailed guide on checking IP reputation for cold emailing in 2026.
Frequently Asked Questions About Temp Email Detection
What is a temp email checker and how does it work?
A temp email checker is a disposable email detector that checks domains against a database of 200+ known burner email providers. It also performs MX record verification, catch-all SMTP testing, and checks SPF and DMARC authentication. Results include a risk score (0-100) and verdict classification.
How to block disposable emails on my signup form?
Validate the domain server-side against a disposable domain list (200+ providers). Also check MX records exist, test for catch-all configurations, and require email confirmation. For real-time form validation, implement an AJAX check that warns users before form submission.
What is a catch-all domain and is it always disposable?
Catch-all domains accept email for ANY address. While disposable providers almost always use catch-all, some legitimate businesses do too. Our temp email checker combines catch-all detection with database matching and authentication checks for accurate classification. Never block catch-all alone.
How to prevent trial hopping with disposable emails?
Block known disposable email domains at signup, require email confirmation, check for catch-all servers, cross-reference IP fraud scores, and use browser fingerprinting to detect the same device creating multiple accounts. Our multi-layer approach stops trial-period abuse effectively.
Why are my emails going to spam in 2026?
High bounce rates from disposable and invalid addresses damage sender reputation. Gmail/Yahoo 2026 guidelines require SPF, DKIM, and DMARC for bulk senders. Clean your list by removing disposable domains, verify authentication records, and check IP blacklist status. Keep bounce rates below 2%.
How to remove disposable emails from my email list?
Export your list, extract domains, paste into our bulk checker (up to 25), remove all flagged as Disposable, delete domains with no MX records, flag catch-all domains for review, and re-verify quarterly as new disposable providers appear constantly.
Is Proton Mail a disposable email service?
No. Proton Mail is a legitimate privacy-focused email provider based in Switzerland, not a disposable service. It provides permanent encrypted mailboxes with strong privacy protections. Our temp email checker correctly classifies Proton Mail, Tuta, Mailfence, and similar services as Privacy Email Providers with a low risk score, distinguishing them from actual disposable services like Mailinator or Guerrillamail that provide temporary self-destructing addresses.
Is there a free API for burner email detection?
Our tool provides a reference implementation with a 200+ burner domain list and live DNS checking. Developers can integrate this approach into signup forms for real-time form validation. Combine domain database checks with MX record queries, SPF/DMARC verification, and catch-all detection for maximum fraud prevention coverage.
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Free Temp Email Checker — No Signup Required
Our temp email checker detects 200+ disposable domains, verifies MX records, checks SPF/DMARC, performs catch-all SMTP detection, and scores risk 0-100. Bulk check up to 25 emails. Protect signup forms from burner emails.