Free Email Syntax & DNS Deliverability Checker
Instant keyless diagnostic inspecting RFC 5322 syntax grammar, authoritative MX records, role accounts, and free email providers.
How Email Checker Works
RFC 5322 Syntax Parse
Validates local-part characters, double dots, quoting, and TLD validity.
Authoritative MX Check
Confirms the domain has active mail exchanger records capable of accepting delivery.
Heuristic Classification
Flags disposable burners, free consumer mailboxes, or shared role distribution aliases.
RFC Engineering Standards
Every check performed by this tool adheres strictly to the Internet Engineering Task Force (IETF) Request for Comments:
- RFC 5322 (Internet Message Format)
- RFC 5321 (SMTP)
- RFC 3696 (Address Syntax Validation)
Common Issues & How to Fix Them
If our diagnostic discovers configuration anomalies, use the remediation steps below:
Remediation: Addresses like info@, billing@, or sales@ often have multiple recipients or low engagement. Prioritize personal corporate addresses for sales outreach.
Remediation: Email contains invalid characters, consecutive dots, or an invalid top-level domain.
Frequently Asked Questions
Does this free email checker open a direct SMTP socket?
This free tool performs syntax and authoritative DNS validation. To test real-time port 25 mailbox existence via direct SMTP handshakes, use the live console on our homepage or our verification API.
What is a role-based email address?
Role-based emails (sales@, support@, contact@) belong to departments or distribution lists rather than individuals. They frequently result in lower open rates and higher spam complaints when cold-emailed.
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Scan IPv4 addresses and domains against authoritative DNS blocklists (Spamhaus, Barracuda, SORBS, SURBL, SpamCop) in parallel.
Verify Real Mailbox Existence in Real-Time
DNS tests only tell you if a server is reachable. BounceLayer's API connects directly to recipient mail servers via port 25 SMTP handshakes to confirm exact mailbox existence in under 140ms.