Email Address Validator
Check any email address before you send to it or accept it at signup. The validator checks syntax, whether the domain can receive mail, disposable providers, role accounts, and common domain typos.
What this checks
Syntax
Practical RFC 5321 rules that real providers enforce.
Deliverable domain
MX lookup confirms the domain can receive mail.
Risk signals
Disposable providers, role accounts, and common typos.
Catch bad addresses before they bounce.
Every hard bounce hurts your sender reputation. Validating at signup and before big sends keeps your bounce rate low and your deliverability intact.
Syntax is the floor
Format checks catch typos, but a well-formed address can still point at a dead domain.
MX proves routing
A domain with no mail exchangers cannot receive email, no matter how valid the address looks.
Risk beats existence
Disposable and role addresses deliver today and bounce or complain tomorrow. Treat them as signals.
Email validation questions.
Can this tool tell if an inbox actually exists?
Not with certainty. It verifies syntax, that the domain can receive mail (MX records), and known risk signals like disposable domains. Only a real delivery attempt proves an inbox exists, and most providers block direct mailbox probing.
Why do MX records matter for validation?
If a domain publishes no MX records, mail to any address at that domain has nowhere to go. Checking MX catches dead domains and typos that pure syntax validation misses.
What is wrong with disposable addresses?
Disposable inboxes expire quickly, so future emails bounce and damage your sender reputation. Most products block them at signup for that reason.
Suppressions handled automatically
SMTPfast tracks bounces and complaints per address and suppresses them automatically, so one bad list upload never snowballs into a reputation problem.
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