Check if an email address
is valid — instantly.
Free, real-time email verification: syntax, MX/domain, and an SMTP check — without ever sending a message to the inbox.
What does this email checker actually check?
This email checker runs four real checks in real time — email syntax validation, an MX/domain lookup, an SMTP handshake with the receiving mail server, and a risk score — to tell you whether an email address is valid and deliverable, without ever sending it a message. It's a complete email address checker and syntax validator in one tool.
- 1
Syntax check
Confirms the address matches valid email format (RFC 5322) and catches typos before anything else runs. This is your first line of defense in email verification.
- 2
MX & domain lookup
Looks up the domain's MX records to confirm it's actually configured to accept mail at all. This checks if the domain exists and can receive email.
- 3
SMTP verification
Connects to the receiving mail server and asks whether the mailbox exists — without delivering an actual message. This is an SMTP email verification that doesn't send a test email.
- 4
Risk scoring
Flags disposable domains, role-based addresses (info@, support@), and catch-all domains that accept everything. This helps you identify risky addresses before you send.
Why verify an email address before you send
Sending to an invalid or risky address doesn't just waste an email — repeated bounces damage your sender reputation and can get future messages routed to spam, even the good ones. That's why you need to verify email addresses before adding them to your list.
98%+
Deliverability accuracy on verified addresses
0.4%
Typical bounce rate for cleaned lists
3
Real checks: syntax, MX/DNS, SMTP
A free alternative to paid email verifiers
Looking for a free alternative to NeverBounce or ZeroBounce? Tools like NeverBounce, ZeroBounce, and Hunter's verifier typically charge per lookup before you've even seen a result. This free email verifier is free to use for one-off lookups, with no signup and no credit card — and when you're ready to verify a full list, AskOptimus gives you 50 free credits every month to do it at scale. It's also a great hunter email verifier alternative.
Verifying more than one email?
Upload a list and verify thousands of addresses at once with the same syntax, MX/DNS, and SMTP checks — plus catch-all, role, and disposable detection, deduped and exported straight to your CRM. It's the ideal email existence checker for bulk lists.
Verify a list — free →// or let your agent do it, via MCP
$ ask-optimus verify_email
--email "name@company.com"
→ valid · 98% confidence
Frequently asked questions about how to verify an email address
How do I check if an email address is valid for free?
Type the address into the checker and click Verify email. It's free for single lookups, with no signup and no credit card — you'll see syntax, MX/domain, and SMTP results in a few seconds. It's a simple email address checker that gives you instant results.
How can I verify an email address without sending a message?
This tool connects directly to the receiving mail server over SMTP and asks whether the mailbox exists, then closes the connection — no message is ever delivered to the inbox. This is how to check email validity without sending.
What does "risky" or "catch-all" mean in a result?
A catch-all domain accepts mail to any address, even ones that don't exist, so we can't fully confirm the specific mailbox — we mark these as risky rather than valid or invalid. This is important when you check if an email exists.
Is this a free alternative to NeverBounce, ZeroBounce, or Hunter's verifier?
Yes. Single lookups are free with no account required, and if you need to verify a full list, AskOptimus includes 50 free credits every month for bulk verification. It's the best free alternative to NeverBounce and a great ZeroBounce free alternative.
Can I verify email lists in bulk, not just one at a time?
Yes — upload a CSV in AskOptimus to verify thousands of addresses at once with the same syntax, MX/DNS, and SMTP checks used here, then export the results or push them straight to your CRM. This is perfect for bulk email verification.
Do you store the emails I check here?
Single lookups are used only to return your result. See our Privacy Policy for full details on data handling. We take your privacy seriously.
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