Email Address Checker

Check email address format and the reachability of the domain and MX records

Features

Two-step verification: format and DNS

Dual confirmation of RFC-compliant format and domain existence via DNS

MX records displayed by priority

View mail server priority and names in a list

Batch verify up to 10 addresses

Judge multiple addresses together at once, separated by line breaks, spaces, or commas

Check results by category

Format, domain, and MX records displayed individually in accordion view

How to Use

Enter email address

Enter up to 10 addresses to check in the input field, separated by line breaks, spaces, or commas

Click the check button

Each address is verified through DNS MX record lookup

Review details in accordion

Expand and view format, domain, and MX records for each email

Copy the addresses confirmed reachable

The "Copy reachable addresses" button lets you copy only the addresses that passed the format, domain, and MX checks all at once

Use Cases

Organize email distribution lists

Extract only reachable addresses before broadcasts or mass mailings

Pre-check account registration

Check whether the domain of the entered address is configured to receive mail

Before sending business email

Check recipient domain MX configuration before sending important inquiries

Clean up old customer lists

Identify invalid addresses in contact lists that haven't been used in a long time

Basic Knowledge

How Email Address Verification Works

You can verify whether an email address has the correct format, if the domain exists, and if a mail server (MX record) is configured to receive mail—all without actually sending an email. You can do this by querying DNS. This method is safe because the recipient is not notified.

What Is an MX Record

An MX record is a DNS configuration that specifies which server receives mail for a given domain. Even without an MX record, mail delivery to the domain's own server may be attempted per specification (implicit MX), but an explicit MX record is the standard for reliable delivery.

What Cannot Be Verified

DNS only shows whether a receiving endpoint exists. It cannot determine whether individual mailboxes actually exist or whether the inbox is full. Whether an email will actually be delivered can only be determined by attempting to send it.