What is an MX lookup?
Quick answerAn MX lookup returns a domain's mail exchanger records: the servers that accept email for it, each with a priority number (lower is tried first). It tells you which email provider a domain uses and is the first check when messages bounce or never arrive.
Reading MX results
- Priority: senders try the lowest number first and fall back to higher ones.
- Hostname: usually reveals the provider (for example, hosts ending in google.com or outlook.com).
- No MX records: the domain cannot receive email, or relies on a fallback A record, which is unreliable.
MX checklist after switching email provider
- Delete the old provider's MX records. Mixed records split your mail between two inboxes.
- Add the new provider's records exactly as given, priorities included.
- Update SPF so the new provider may send for you, and check it with the SPF & DMARC checker.
- Wait for the old TTL to expire, then confirm both resolvers here show the same result.
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Mx lookup FAQ
Is this mx lookup free?
Yes, unlimited and free with no sign-up. Queries go from your browser to public DNS-over-HTTPS resolvers (Cloudflare and Google).
Why do two resolvers show different results?
DNS answers are cached for the record's TTL. Right after a change, some resolvers still serve the old value. Wait for the TTL to expire and check again.
Can I look up a subdomain?
Yes. Type the full name, for example mail.example.com or _dmarc.example.com.