Email Verifier Online
Free Email Verification Tool & Deliverability Checker
Use our free email verifier online to check email address validity without sending a test mail. This real-time email validator performs syntax validation, MX record verification, SMTP handshake checking, disposable email detection, catch-all domain identification, role-based address flagging, and SPF/DKIM/DMARC record analysis. Verify single emails or use our bulk email validator to clean up to 25 addresses at once. Protect your sender reputation, reduce hard bounces, and improve email deliverability.
Quick Answer: What Is an Email Verifier Online?
An email verifier online validates email addresses through multiple checks without sending an actual email. It performs RFC 5322 syntax validation, MX record verification to confirm the domain has a mail server, SMTP handshake to check if the specific mailbox exists, disposable email detection (Mailinator, Guerrillamail), catch-all domain identification, role-based address flagging (info@, admin@), and SPF/DKIM/DMARC record analysis. Our email deliverability checker scores each email from 0-100 and supports bulk validation of up to 25 emails.
Verify Email Without Sending
Enter an email to check email address validity via SMTP handshake, MX records, and deliverability scoring.
Robert Harrison
OSINT & Network Utility Expert
Robert specializes in email infrastructure, DNS management, SMTP protocol analysis, and network security. He helps email marketers, developers, and businesses verify email addresses, troubleshoot deliverability issues, configure SPF/DKIM/DMARC authentication, and maintain clean mailing lists for optimal sender reputation.
View All Articles by Robert HarrisonWhat Is an Email Verifier Online and Why Does It Matter?
An email verifier online is a free email verification tool that validates email addresses through multiple technical checks — all without sending a test message. When you check email address validity through our tool, it performs RFC 5322 syntax validation, MX record verification to confirm the domain has an active mail server, an SMTP handshake with the recipient's server to verify the mailbox exists, disposable email detection (flagging providers like Mailinator and Guerrillamail), catch-all domain identification, role-based address detection, and SPF/DKIM/DMARC authentication record analysis.
According to Wikipedia's article on email addresses, the format defined by RFC 5322 specifies a local-part, an @ symbol, and a domain with strict rules for valid characters. Our real-time email validator enforces these standards while going far beyond basic syntax — performing live infrastructure checks that determine whether an email will actually reach a human inbox or bounce back.
Email list decay is inevitable. Industry data shows that approximately 22-25% of email addresses become invalid each year due to job changes, domain expirations, company closures, and abandoned accounts. Sending to these dead addresses damages your sender reputation, increases hard bounce rates, and can get your sending IP blacklisted by providers like Gmail, Outlook/Office 365, and Yahoo. Our email deliverability checker helps you maintain a clean list.
Key Fact: Our email verifier online performs 10+ checks per email: syntax validation, MX records with priority, SMTP handshake verification, catch-all detection, disposable/temporary email flagging, role-based detection, free provider identification, SPF record check, DKIM hint detection, and DMARC record analysis. Each email receives a deliverability score from 0-100.
How to Verify Email Addresses Without Sending a Test Mail
Our email verifier online uses a technique called SMTP handshake verification to check whether a mailbox exists — completely without sending any email. The recipient never receives a message or notification. Here is how it works.
The SMTP Handshake Process
The tool connects to the recipient's mail server on port 25 and initiates the SMTP protocol: it sends a HELO command to identify itself, then a MAIL FROM command with a verification address, followed by a RCPT TO command with the email being checked. The server responds with a status code: 250 means the mailbox exists and accepts mail (valid), 550/553 means the mailbox does not exist (invalid — will hard bounce), and 450/451 means the server is temporarily rejecting the request (greylisting).
Why SMTP Verification Has Limits
Some servers (particularly Gmail and Outlook/Office 365) do not reveal whether a specific mailbox exists during SMTP handshake for security reasons. They accept all RCPT TO commands and then bounce invalid ones later. This is why our tool combines SMTP results with MX record analysis, domain reputation, and authentication records for a comprehensive deliverability score. For DNS-level analysis of any domain's mail configuration, use our DNS Lookup Tool to check MX, TXT, and other records directly.
Developer Tip: Our email verification tool is ideal for API for developers integrating real-time validation into signup forms, CRM cleaning workflows, and lead generation verification pipelines. Verify emails at the point of collection to prevent bad data from entering your system.
How to Remove Disposable and Temporary Emails from Your List
Disposable emails (also called temporary or throwaway emails) are addresses created by services like Mailinator, Guerrillamail, Tempmail, and Yopmail that expire after minutes or hours. They are used by people who want to bypass email-gated content without providing their real address. Sending marketing emails to these addresses is pointless — they will either bounce or never be read.
Our email verifier online maintains a database of 50+ known disposable email providers and instantly flags any address from these domains. When you check email address validity, disposable emails receive a "Risky" verdict with a reduced deliverability score. For dedicated disposable detection, also use our Temporary Email Checker tool which focuses specifically on identifying throwaway addresses.
Role-Based Email Detection
Role-based addresses like info@, admin@, support@, and sales@ are typically group mailboxes that are not monitored by a single person. While they are technically valid, they have lower engagement rates and higher complaint rates. Many email marketing platforms (Mailchimp, Klaviyo, SendGrid) recommend excluding role-based addresses from marketing campaigns. Our tool detects 25+ common role-based prefixes automatically.
Free Tool to Check If an Email Is a Catch-All Address
A catch-all (or accept-all) domain is configured to accept emails to ANY address at that domain, regardless of whether the specific mailbox exists. For example, if company.com is catch-all, then random-string-12345@company.com would still be accepted by the server. This makes email verification challenging because the SMTP handshake always returns "accepted."
How Our Tool Detects Catch-All Domains
After verifying the target email, our real-time email validator sends a second RCPT TO command with a randomly generated, obviously non-existent address at the same domain. If the server accepts this random address too, the domain is flagged as catch-all. Catch-all domains receive an "uncertain" classification because while the domain accepts mail, we cannot confirm the specific mailbox exists.
How to Handle Catch-All Results
For marketing campaigns, segment catch-all emails into a separate list and send with lower volume initially to monitor bounce rates. If bounce rates stay low, the addresses are likely valid. If bounces spike, remove them. Many Shopify and Mailchimp users encounter catch-all results because business domains commonly use catch-all configurations.
Why Are My Marketing Emails Going to Spam in 2026?
If your emails are landing in spam folders, the root causes typically involve your list quality, authentication records, and sender reputation. Our email deliverability checker addresses the first two directly.
1. High Bounce Rate from Invalid Emails
ISPs like Gmail, Outlook, and Yahoo monitor your hard bounce rate closely. If it exceeds 2%, your sending IP reputation drops dramatically. Invalid emails, closed mailboxes, and non-existent domains all cause hard bounces. Clean your list with our bulk email validator before every campaign. Check if your IP is already blacklisted with our IP Blacklist Checker.
2. Missing SPF, DKIM, and DMARC Records
SPF (Sender Policy Framework) tells receivers which servers are authorized to send email for your domain. DKIM (DomainKeys Identified Mail) adds a cryptographic signature to verify message authenticity. DMARC (Domain-based Message Authentication) tells receivers how to handle emails that fail SPF or DKIM. Our tool checks all three records and displays the full policy values. Learn more about DNS records in our DNS Lookup Tool.
3. Sending to Spam Traps
Spam traps are email addresses operated by ISPs and anti-spam organizations to identify senders with poor list hygiene. Pristine traps are addresses that never signed up for anything — if you email them, you scraped or bought your list. Recycled traps are abandoned addresses reactivated to catch senders who never clean their lists. Regular validation with our tool removes high-risk addresses before they damage your reputation. Read our detailed guide on checking IP reputation for bulk email marketing.
Critical: Gmail's 2024 sender requirements mandate SPF or DKIM authentication, DMARC records, and one-click unsubscribe for bulk senders (5,000+ emails/day). Non-compliance results in delivery failures. Our tool verifies SPF/DKIM/DMARC for any email domain instantly.
Hard Bounce vs Soft Bounce: Understanding Email Deliverability
Understanding bounce types is critical for maintaining sender reputation and optimizing email deliverability.
Hard Bounce — Permanent Failure
A hard bounce means the email permanently cannot be delivered: the mailbox does not exist, the domain has no mail server, or the address is syntactically invalid. Hard bounces should be immediately removed from your list — ISPs penalize senders with high hard bounce rates. Our email verifier online prevents hard bounces by checking addresses before you send.
Soft Bounce — Temporary Failure
A soft bounce means the email temporarily cannot be delivered: the recipient's inbox is full, the server is down, or the message is too large. Soft bounces may resolve on their own, but addresses that consistently soft bounce should be removed after 3-5 attempts.
Greylisting
Greylisting is a spam prevention technique where the receiving server temporarily rejects emails from unknown senders (returning a 450 code). Legitimate mail servers retry the delivery after a delay, at which point the email is accepted. Our SMTP check detects greylisting responses and reports them separately from rejections. For comprehensive email reputation analysis, see our guide on what is IP reputation score.
Verify Corporate Email Addresses with SMTP Check
Verifying corporate email addresses requires understanding how enterprise mail servers behave. Our tool handles the nuances of major email providers including Microsoft 365 (Outlook), Google Workspace (Gmail), and self-hosted exchange servers.
Gmail and Google Workspace Validation
Google Workspace servers (identified by MX records like aspmx.l.google.com) accept SMTP handshakes but may not reveal individual mailbox status. Our tool detects Google MX records and adjusts the confidence scoring accordingly. Gmail personal addresses follow similar patterns.
Microsoft 365 / Outlook Validation
Office 365 servers (MX records pointing to *.mail.protection.outlook.com) generally respond accurately to RCPT TO commands, making them more reliable for SMTP verification. Our email verification tool identifies Microsoft infrastructure through MX record analysis.
Self-Hosted Mail Servers
Companies running their own mail infrastructure (Postfix, Exim, Exchange on-premises) typically give the most accurate SMTP responses. Our tool handles all major SMTP server implementations. Check the domain's SSL certificate with our SSL Checker and verify the domain registration with our WHOIS Lookup for complete due diligence.
Best Email Validator for Shopify and Mailchimp Users
E-commerce platforms like Shopify and email marketing tools like Mailchimp, Klaviyo, and SendGrid all benefit from email verification at two critical points: at collection (signup forms) and before campaigns (list cleaning).
At-Collection Verification
Integrating email verification into your Shopify checkout or newsletter signup form catches typos and fake emails in real-time. Our real-time email validator provides instant feedback so users can correct mistakes before submitting. This prevents invalid addresses from ever entering your database.
Pre-Campaign List Cleaning
Before every major email campaign, run your list through our bulk email validator. Paste up to 25 emails at once to check syntax, MX records, disposable status, and deliverability scores. Remove all "invalid" and "risky" verdicts before sending. This is especially critical for Shopify and Mailchimp users because both platforms charge based on subscriber count — paying for invalid addresses wastes budget. Secure your accounts with a strong password from our Password Generator.
Bulk Email List Cleaning: Step-by-Step Guide
Our bulk email validator makes email list cleaning fast and thorough. Follow this workflow for optimal results.
- Step 1: Export your email list from your CRM, Mailchimp, or Shopify admin panel.
- Step 2: Paste emails into our bulk tool (up to 25 per batch).
- Step 3: Review results — remove all emails with "Invalid" verdict (hard bounce risk).
- Step 4: Flag "Risky" emails (disposable, role-based) for separate treatment or removal.
- Step 5: Note "Uncertain" results (catch-all domains) — send with caution and monitor bounces.
- Step 6: Keep "Deliverable" emails in your main sending list.
- Step 7: Re-verify your list every 3-6 months to catch newly invalid addresses.
- Step 8: Check your sending IP reputation with our IP Blacklist Checker.
- Step 9: Verify DNS authentication records (SPF/DKIM/DMARC) are properly configured.
- Step 10: Monitor your RBL status after sending campaigns.
Best Practice: Clean your email list before every major campaign, not just once a year. Industry leaders clean lists monthly and verify all new addresses at the point of collection. A clean list with 10,000 engaged subscribers outperforms a dirty list of 100,000.
Complete Email Deliverability Audit Checklist
- Step 1: Verify email addresses with our email verifier online — remove invalid and risky addresses.
- Step 2: Check SPF, DKIM, and DMARC records are configured for your sending domain.
- Step 3: Verify your sending IP is not blacklisted with our IP Blacklist Checker.
- Step 4: Check domain MX records with our DNS Lookup Tool.
- Step 5: Verify domain registration and age with our WHOIS Lookup.
- Step 6: Check your IP reputation score before sending.
- Step 7: Ensure your server has valid SSL with our SSL Checker.
- Step 8: Remove disposable emails — cross-check with our Temp Email Checker.
- Step 9: Verify proper HTTP→HTTPS redirects on landing pages with our Redirect Checker.
- Step 10: Check security headers on your email landing pages with our Headers Analyzer.
Frequently Asked Questions About Email Verification
Q What is an email verifier and how does it work?
An email verifier online validates addresses through syntax validation, MX record checks, SMTP handshake, disposable detection, catch-all identification, and SPF/DKIM/DMARC analysis — all without sending an email. Our tool scores deliverability from 0-100.
Q How to verify email without sending a test mail?
Our tool performs SMTP handshake on port 25 — connecting to the mail server, sending HELO and RCPT TO commands. The server responds with 250 (valid) or 550 (invalid) without any email being delivered. The recipient never knows they were checked.
Q How to remove disposable and temporary emails?
Our email verifier checks against 50+ known disposable email providers (Mailinator, Guerrillamail, Tempmail). Flagged emails receive "Risky" verdict. Use our bulk email validator for list cleaning or our dedicated Temp Email Checker.
Q What is a catch-all email domain?
A catch-all domain accepts emails to ANY address regardless of mailbox existence. Our tool detects this by testing a random address after the target. Catch-all results are "uncertain" — send cautiously and monitor bounces.
Q Why are my emails going to spam?
Common causes: high hard bounce rate, missing SPF/DKIM/DMARC records, spam trap hits, poor sender reputation. Clean your list with our email verifier, check authentication records, and verify your IP with our IP Blacklist Checker.
Q What are SPF, DKIM, and DMARC?
SPF = which servers can send email for your domain. DKIM = cryptographic signature for authenticity. DMARC = policy for handling failures. Our tool checks all three and displays full record values. Essential for Gmail and Outlook compliance.
Q Can I use bulk email validator for list cleaning?
Yes. Our bulk email validator accepts up to 25 emails per batch. Paste one per line — each gets syntax, MX, disposable, and deliverability checks. Remove "invalid" and "risky" results before campaigns. Essential for Shopify and Mailchimp users.
Q How to verify corporate emails with SMTP?
Enter the corporate email — our tool performs SMTP handshake with the company's mail server. Microsoft 365 and Google Workspace servers respond to RCPT TO commands. Our tool identifies the provider via MX records and adjusts scoring for catch-all domains common in enterprises.
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Free Email Verifier — No Signup Required
Our email verifier online performs SMTP handshake, MX record checks, disposable detection, catch-all identification, and SPF/DKIM/DMARC analysis. Scores deliverability 0-100. Bulk validate up to 25 emails at once.