Mail Exchange & MX Record Lookup.
Inspect inbound mail servers, check host priority rankings, verify IPv4/IPv6 resolution, and confirm mail provider routing in real time.
What this lookup inspects:
Enter any domain on the left. In under 50 milliseconds, Sortwell queries authoritative root nameservers and validates your mail exchange architecture:
Understanding Mail Exchange Routing.
Without valid MX records, no mailbox provider (such as Google or Outlook) can route incoming messages to your organization. Learn the core principles of RFC 5321 mail exchange architecture.
What is an MX record and how does priority work?
A Mail Exchange (MX) record tells the internet which mail servers accept incoming emails for your domain. Priority numbers determine server preference — lowest numbers (e.g. 1 or 5) receive traffic first, while higher numbers (e.g. 10 or 20) act as redundant backups.
What happens if my domain has no MX records?
If a domain lacks MX records, receiving MTAs may fall back to checking the primary A record (RFC 5321 §5.1). However, modern enterprise providers like Gmail, Yahoo, and Outlook will reject the email with a 550 5.1.2 Host unknown delivery bounce.
How long do MX record DNS updates take to propagate?
DNS propagation depends on the Time-to-Live (TTL) configured on your previous DNS records. Typical propagation finishes between 15 minutes and 4 hours globally.
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