Check if an email address is valid
Format check, MX records, and live SMTP verification - all in one step. No account needed. 3 free checks per day.
What gets checked
Three layers of verification, from syntax to live server confirmation.
Format validation
Confirms the address follows valid email syntax before anything else.
MX record check
Looks up the domain's mail exchange records to confirm the domain can receive email.
SMTP verification
Connects directly to the mail server to confirm the mailbox exists without sending anything.
Catch-all detection
Flags domains that accept all addresses - useful for outreach since catch-alls can mask invalid inboxes.
Bad emails hurt your outreach
A bounce rate above 2% can get your sending domain flagged. Every invalid email you send chips away at your sender reputation - sometimes permanently.
Verifying before you send takes seconds and protects months of domain warm-up.
Need more than 3 per day?
WebLeads Starter includes 3,000 email verifications per month - plus Google Maps prospecting, decision maker emails, and CSV export. Starts at $24/mo.
Common questions
What does "catch-all" mean?
A catch-all domain accepts every email sent to it, regardless of whether the specific mailbox exists. This means SMTP verification returns positive even for made-up addresses. If a domain is catch-all, treat the result as uncertain.
Will you send a test email to verify?
No. The SMTP check connects to the mail server and simulates the start of a conversation without delivering any message. The mailbox owner never sees anything.
Why does the result sometimes show "Unknown"?
Some mail servers use greylisting or block verification attempts entirely. In those cases we can confirm the domain is real (MX exists) but can't verify the specific inbox.
How is this different from just checking email format?
Format validation only checks if the address looks right (like having an @ sign). SMTP verification actually contacts the mail server. An address can be perfectly formatted and still bounce - this tool catches that.
Why only 3 free verifications per day?
SMTP verification uses real server connections. To keep this tool free for everyone, we limit anonymous use. Signing up for a WebLeads account gives you up to 3,000 verifications per month.