Enter a domain to look up its MX records
What this tool does
Free MX record lookup — check mail exchange DNS records and identify email providers for any domain
How MX records work and why they matter for email deliverability
This MX record lookup tool queries the DNS for any domain's Mail Exchanger (MX) records using Cloudflare's and Google's DNS-over-HTTPS APIs. MX records are the DNS entries that tell the internet where to deliver email for a domain. Without correct MX records, no email can be received. This tool shows all MX records sorted by priority and identifies the email service provider being used.
Common use cases: verifying MX records after migrating to a new email provider, checking whether MX records have propagated after a DNS change, diagnosing email delivery failures by confirming the correct mail servers are configured, and researching which email platform a company uses.
Features and capabilities
Live DNS Query
Uses Cloudflare DoH for accurate, real-time results with Google DNS as fallback.
Priority Sorted
Records displayed sorted by priority — lowest number = highest priority server.
Provider Detection
Identifies Google Workspace, Microsoft 365, Zoho, Proton, Fastmail, SendGrid, and more.
Instant Results
Queries complete in under 1 second for most domains.
All Records
Shows every MX record, not just the primary server.
No Software
Runs entirely in browser — no dig, nslookup, or command line needed.
FAQ
Frequently asked questions about MX records and email DNS configuration
What is an MX record?
An MX (Mail Exchanger) record is a DNS record that specifies the mail servers responsible for accepting email for a domain. When someone sends an email to user@example.com, their email client or server queries the DNS for example.com's MX records, then connects to the mail server listed there to deliver the message. A domain can have multiple MX records with different priorities — lower numbers have higher priority. If the primary server is unavailable, the sender tries the next-lowest priority server.
What does the priority number mean?
The MX record priority (also called preference) is a number that determines which mail server to use first. Lower numbers = higher priority. A mail server trying to deliver email will always attempt the lowest-priority-number server first. If that server is unreachable or returns a temporary error, it tries the next one. Priority 10 is tried before priority 20. Having multiple MX records with different priorities provides redundancy — if one mail server goes down, email can still be delivered to a backup server.
Why does a domain have multiple MX records?
Multiple MX records provide redundancy and load distribution. The primary MX (lowest priority number) handles most incoming mail. If it's unavailable, senders fall back to secondary MX records with higher priority numbers. Google Workspace, for example, uses 5 MX records at priorities 1, 5, 5, 10, and 10. Microsoft 365 uses two servers at priority 0 and 10. Having only one MX record is a risk — if that server goes down, all incoming email bounces or queues on the sender's side.
How long do MX record changes take to propagate?
MX record changes propagate based on the TTL (Time to Live) of the DNS record. Most domains set MX record TTLs between 300 seconds (5 minutes) and 3600 seconds (1 hour). After changing MX records, resolvers around the world will continue using the old records until their cached copies expire. Full global propagation typically takes 1–4 hours for short TTLs, up to 48 hours for long TTLs. When migrating email providers, lower the TTL to 300 before making changes to speed up propagation.
What does it mean if a domain has no MX records?
If a domain has no MX records, most mail servers will fall back to the domain's A record (the IP address of the domain itself) to attempt delivery. This is called implicit MX. Some strict mail servers will reject delivery entirely if no MX record exists. For domains that should never receive email (like subdomains used only for web services), it's best practice to publish a null MX record (priority 0, exchange '.') to explicitly signal this and prevent delivery attempts.
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