MX Record Lookup
List the mail servers for any domain, in priority order, with their IP addresses and the email provider behind them.
How it works
MX records tell other servers where to deliver mail for a domain. Lower priority numbers are tried first.
No MX record usually means the domain can't receive email at all, which is a strong sign an address on it will bounce. The provider label (Google Workspace, Microsoft 365, Mimecast, Proofpoint...) also tells sales teams what they're up against.
Automate it with the API
Run this check for every address in your product, from any language.
curl -X POST https://www.mailrambo.com/v1/verify \
-H "Authorization: Bearer $MAILRAMBO_KEY" \
-H "Content-Type: application/json" \
-d '{"email": "jane@acme.com"}'API reference · Get a free API key
Frequently asked questions
What if a domain has no MX record?
Senders fall back to the domain's A record, but most such domains don't run a mail server. Treat addresses there as undeliverable unless verified.
What is a null MX?
A single MX record pointing to '.', which explicitly says the domain accepts no email (RFC 7505).
Related tools
Email Verifier
Check if an email address exists and will accept mail.
Email Domain Health Checker
Full deliverability report: MX, SPF, DKIM, DMARC, BIMI and PTR with an A-F grade.
DNS Records Lookup
A, AAAA, MX, NS, TXT, CNAME, SOA and CAA records in one view.
Reverse DNS (PTR) Lookup
Check an IP's PTR record and whether it's forward-confirmed.
Run these checks from your code
Verify addresses at signup, clean lists and read SPF/DKIM/DMARC with one API call. 100 free verifications a month, test keys that cost nothing, and the API on every plan.