Free diagnostic
Inspect a domain's published MX records, priorities, and mail exchanges without probing a mailbox or retaining the submitted domain.
DNS
live evidence
No SMTP
mailbox probing
0
stored submissions
MX records identify the servers a domain publishes for inbound email. Priority values describe preference order, while the exchange names identify the receiving infrastructure.
An MX record does not prove that a specific mailbox exists, that SMTP will accept mail, or that an outbound message will reach the inbox. Those are separate questions with different evidence.
Live diagnostic
This anonymous tool is rate limited and does not retain submitted input. It reports observable evidence without promising delivery, authentication alignment, or inbox placement.
No SMTP mailbox probing, account lookup, or tenant data is used.
Related
Understand priorities, fallbacks, and common errors.
Classify recipient risk with layered evidence.
Track MX and authentication drift over time.
See how this workflow applies to teams running developer testing, sdks, webhooks, and ci/cd.
Read the supporting guide for practical context around developer testing, sdks, webhooks, and ci/cd.
Review request and response patterns for single validation, bulk verification, suppression, and webhook flows.
Use the REST API reference when validation, bulk jobs, webhooks, reports, or usage need to run from your own systems.
Verify signed callbacks for bulk jobs, reports, sandbox events, delivery logs, and operational automation.
Use the Node and Python clients for validation, sandbox capture, report access, and webhook verification.
Compare validation volume, monitoring, API access, reporting, and workspace limits by plan.
FAQ
