What layers exist in email validation?

Syntax checks RFC-compliant local-part and domain structure. DNS checks confirm the domain exists and has usable MX (or A fallback where applicable). SMTP-level checks may probe mailboxes without sending mail, depending on provider policy. Each layer catches different failure modes.

Are disposable email domains detectable?

Maintained blocklists flag known disposable providers, but new domains appear constantly. Treat disposable detection as probabilistic; combine with rate limits, phone verification, or payment for high-risk flows.

What is a catch-all domain?

A domain that accepts SMTP for any local-part. Validation may report “OK” for nonexistent mailboxes because the server accepts everything during RCPT TO. Marketing lists degrade silently on catch-alls; segment them and monitor engagement.

Why check MX records?

Without MX (or acceptable fallback), mail cannot be delivered. Misconfigured MX after migrations is common. Cross-check live DNS with the [DNS lookup tool](/dns-lookup) when you change DNS hosts.

Does validation guarantee inbox placement?

No. Authentication (SPF/DKIM/DMARC), IP reputation, content, and recipient engagement dominate placement. Validation reduces hard bounces and obvious typos; use [IP blacklist](/ip-blacklist) checks for outbound reputation issues.

Email Validator

v1.0.0

Instantly validate any email address. Check syntax, domain, and MX records for accurate deliverability status.

Validation results will appear here

Check whether an email address is structurally sound, whether its domain can receive mail, and common risk signals—without replacing your ESP’s bounce handling.

Read the full guide →

Frequently Asked Questions

What layers exist in email validation?: Syntax checks RFC-compliant local-part and domain structure. DNS checks confirm the domain exists and has usable MX (or A fallback where applicable). SMTP-level checks may probe mailboxes without sending mail, depending on provider policy. Each layer catches different failure modes.
Are disposable email domains detectable?: Maintained blocklists flag known disposable providers, but new domains appear constantly. Treat disposable detection as probabilistic; combine with rate limits, phone verification, or payment for high-risk flows.
What is a catch-all domain?: A domain that accepts SMTP for any local-part. Validation may report “OK” for nonexistent mailboxes because the server accepts everything during RCPT TO. Marketing lists degrade silently on catch-alls; segment them and monitor engagement.
Why check MX records?: Without MX (or acceptable fallback), mail cannot be delivered. Misconfigured MX after migrations is common. Cross-check live DNS with the [DNS lookup tool](/dns-lookup) when you change DNS hosts.
Does validation guarantee inbox placement?: No. Authentication (SPF/DKIM/DMARC), IP reputation, content, and recipient engagement dominate placement. Validation reduces hard bounces and obvious typos; use [IP blacklist](/ip-blacklist) checks for outbound reputation issues.