MX Lookup — Check Mail Server Records Online
Paste domains or addresses and this MX lookup queries each exact domain's mail-server records over DNS-over-HTTPS, falling back to the registrable domain only when DNS is inconclusive. Only domain names leave your browser — never addresses or list contents — and unreachable DNS stays unknown instead of guessing.
- 100% in your browser
- No signup · no uploads
- Free to use
drop files here
Results
Nothing processed yet. Add content above and press the action button — everything runs locally in this tab.
History
Optionally remember runs on this device, sealed with your passphrase. Off by default; entries expire after 30 days.
Expires after 30 days; forgetting the passphrase erases access permanently.
How it works
- 01
Add your content
Paste text or drop TXT, CSV, XLSX, DOCX and PDF files into the workspace.
- 02
Run the tool
One press runs the pipeline locally in a Web Worker. Change the options and results update automatically.
- 03
Copy or download
Export results as TXT, CSV or JSON. Your content is never uploaded.
What an MX lookup answers
An MX lookup asks DNS which mail servers a domain publishes. It answers one narrow question — can this domain receive mail at all — and says nothing about whether a specific mailbox exists. That makes it a cheap pre-filter: domains with no MX records can be quarantined before you spend verification budget or reputation on them.
This tool queries the exact address domain first, because mail subdomains can publish their own records. Only when DNS is inconclusive does it consult the registrable parent, and unreachable DNS is reported as unknown rather than guessed.
Reading the statuses
Accepts-mail means MX records were published. No-mx means the lookup completed and found none — the domain cannot receive mail as queried. Unknown means DNS could not be reached or refused to answer; treat it as 'try again later', not as a verdict.
- accepts-mail → keep; still validate the address itself
- no-mx → quarantine or drop the domain slice
- unknown → retry later; never delete on unknown
Privacy model
The lookup runs only when you click, sends domain names only over DNS-over-HTTPS, and never transmits addresses, pasted text or file contents. Up to 100 unique domains per run keep the check fast and abuse-resistant.
Last reviewed: 2026-09-16 · By the Email Extractor Team · About our privacy-first approach
Keep reading
MX records explained for list owners
What MX proves, what unknown means, and pipeline order.
Email list hygiene and validation
Where MX checks fit in the validation pipeline.
Reduce bounce rate with a clean list
How dead domains become hard bounces.
Role-based addresses in outreach
What survives even when MX checks pass.
Frequently asked questions
What does an MX record prove?
Only that a domain publishes mail servers — not that a specific mailbox exists or accepts mail. Pair this with the Email Validator before any send.
What leaves my browser when I run this?
Domain names only, sent to a DNS-over-HTTPS provider after you click run. Addresses, pasted text and file contents never leave the tab.
Why did a subdomain differ from its parent domain?
Mail subdomains can publish their own records. This tool queries the exact domain first and consults the registrable parent only when DNS is inconclusive.