Layered verification
Syntax, Unicode domains, MX records, SMTP responses, and typo suggestions contribute separate evidence to the result.
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05Open-source build
Email Checker
An email verification toolkit that combines syntax checks, MX lookup, SMTP probing, and bulk processing without sending a message.
sagnik11/email-checker
05
01Address input
02Syntax and MX
03SMTP handshake
04Structured verdict
Purpose
The reason for the build
A regex can tell you whether an address looks plausible. Email Checker follows the address through DNS and the receiving mail server so an operator can make a better decision before adding it to a workflow.
Architecture
How the pieces connect
The validation pipeline normalizes the address, checks syntax and domain records, detects disposable or role-based mailboxes, and can perform an SMTP handshake. The package exposes the result through a library, CLI, bulk worker, and hosted interface.
Capabilities
What the project handles
Mailbox classification
Disposable providers, role addresses, and common consumer domains receive explicit labels.
Bulk workflows
Queue-based processing and greylist-aware retries support lists that cannot finish inside one request.
Multiple interfaces
Developers can run a single check from code, use the CLI, process a file, or try the hosted web interface.
Build notes
Constraints that shaped it
01
SMTP servers vary in how much mailbox information they reveal, so the output keeps each check visible instead of hiding uncertainty behind one score.
02
The verifier does not send a message to the target address during its checks.
Tools and systems
- TypeScript
- Node.js
- DNS
- SMTP
- CLI
- Bulk workers