Email Checker
Check an email address for valid syntax, real MX records, disposable domains, and role-based inboxes — in about a second.
What this checker actually verifies
Email validation happens in layers, and each one is a different kind of certainty. This free tool runs the first three, honestly, and tells you plainly where it stops.
- Syntax — is the address well-formed under RFC 5322? Catches typos and malformed input.
- Domain and MX — does the domain exist, and does it publish mail servers? If not, mail to it hard-bounces every time. This is a real DNS lookup, not a guess.
- Classification — is the domain disposable, is the address role-based, is it a free consumer provider?
- Mailbox existence (SMTP) — not performed here. See below.
The layer we do not run for free
Proving that [email protected]
exists — rather than just that example.com
accepts mail — means connecting to the mail server and asking it. Every address at a domain
shares the same MX records, so DNS alone can never distinguish a real mailbox from an invented one.
We do not run that check from a public, keyless endpoint, for two reasons. It would be a free mailbox-enumeration service for anyone who found it. And mail providers throttle and blocklist IP addresses that probe them, so an unmetered public tool would burn the sending reputation that our paying customers rely on.
When a mailbox-level answer is what you need, that is precisely what the Mailvalid API is for — single addresses or bulk lists, with SMTP confirmation and catch-all detection. You get 100 free credits on signup.
Related checks
To see where a domain's mail is hosted, use the MX lookup. To check whether a domain is a throwaway provider, use the disposable checker. To audit whether a domain's own outbound mail is authenticated, check its SPF, DKIM and DMARC records.
Frequently asked questions
Does this tool tell me whether the mailbox exists?
No, and any free tool claiming otherwise is guessing. This checker verifies syntax and looks up the domain's real MX records, which proves the domain can receive mail. Confirming that one specific mailbox exists requires an SMTP conversation with the mail server, which we deliberately do not run from a public endpoint. The Mailvalid API does exactly that, with 95%+ accuracy.
Why won't you do the SMTP check for free?
Two reasons. A public endpoint that opens SMTP connections is a free mailbox-enumeration tool for anyone who finds it. And mail servers rate-limit and blocklist the IPs that probe them, so unmetered public probing would destroy the sending reputation our paying customers depend on.
What is a role-based address?
An address tied to a function rather than a person: info@, support@, sales@, admin@. They are usually shared by several people, are much likelier to generate spam complaints, and often have low engagement. They are perfectly deliverable — you just want to know before adding one to a marketing list.
What does 'disposable' mean here?
The domain is a throwaway inbox provider like Mailinator or 10minutemail. Addresses on these domains work for a few minutes and then vanish. Signups using them almost never convert, and they inflate your list while depressing deliverability. We check against a list of more than 159,000 such domains.
Is a free-provider address a problem?
Not at all — gmail.com and outlook.com addresses belong to real people. We flag them only because some businesses want to route consumer signups differently from corporate ones. Never block them.
Do you store the addresses I check?
We cache the DNS result for the domain, not the address, so that a script checking gmail.com ten thousand times costs one DNS query. Nothing about an individual address is retained.
More free tools
MX Lookup
See which mail servers receive a domain's email.
SPF Checker
Parse SPF and count the RFC 7208 DNS lookups.
DKIM Checker
Find DKIM selectors and check key strength.
DMARC Checker
Inspect your DMARC policy and reporting setup.
Disposable Checker
Detect throwaway and temp-mail domains.
Blacklist Checker
Check an IP or domain against DNS blocklists.
Need to verify a whole list?
This tool stops at DNS. The Mailvalid API confirms whether an individual mailbox actually exists over SMTP — in bulk, with 95%+ accuracy. Start with 100 free credits, no credit card.