MX & Email Health Checker
Inspect Mail Exchange (MX) server priorities, verify SPF (Sender Policy Framework) whitelist records, and validate DMARC authentication policies.
Enter Domain
Type any domain name (e.g. google.com, github.com, yourcompany.com).
Query DNS Over HTTPS
Our engine queries Cloudflare and Google DoH for MX, SPF, and DMARC TXT records.
Inspect Mail Servers
View all host priority tiers, resolved server hostnames, and deliverability records.
Displays exact preference numbers so you can audit primary and failover servers.
Instantly flags missing sender authentication policies that cause email deliverability failures.
Copy the full mail infrastructure audit payload to your clipboard in formatted JSON.
- Ensure your MX record hostnames point directly to A/AAAA records and NEVER to a CNAME, per RFC 2181.
- Set up a DMARC policy with at least 'p=none' to monitor deliverability before enforcing 'p=reject' on unauthorized senders.
Frequently Asked Questions about MX Records
Helpful answers to common questions about checking username availability, domain extensions, and registration.
What is an MX (Mail Exchange) record?
An MX record is a DNS resource record that directs email sent to your domain to the correct mail servers responsible for accepting incoming mail.
What do the preference or priority numbers mean on MX records?
The priority number tells sending mail servers which server to attempt delivery to first. Lower numbers have higher priority (e.g., priority 5 is attempted before priority 10). If the primary server is unreachable, the backup server receives the messages.
Why are SPF and DMARC records critical alongside MX?
While MX records specify where incoming emails arrive, SPF (Sender Policy Framework) and DMARC (Domain-based Message Authentication) verify who is authorized to send emails from your domain. Without them, spoofers can impersonate your brand, causing legitimate emails to land in spam folders.
How long does it take for MX record changes to propagate?
MX propagation typically takes from a few minutes to up to 24-48 hours depending on your previous TTL (Time-To-Live) value set with your DNS registrar or nameserver provider.
Can I have multiple MX records from different providers simultaneously?
Generally no. Having mixed MX records (such as Google Workspace and Microsoft 365 simultaneously) causes split-brain routing where incoming emails are unpredictably routed to different inboxes.