MX Record Checker
Verify mail server DNS records, test SMTP connectivity, and check email deliverability. Essential for email administrators to ensure reliable email delivery and troubleshoot routing issues.
Check MX Records
đĄ Understanding MX Records
âĸ Priority numbers determine mail server preference (lower = higher priority)
âĸ Multiple MX records provide redundancy and improve reliability
âĸ SMTP connectivity verifies servers are actually accepting mail
âĸ Response time indicates server performance and network latency
âĸ Backup servers ensure email delivery even if primary server fails
What We Check
đ§ MX Records
DNS lookup of mail exchange records showing priority and mail server hostnames.
đ SMTP Connectivity
Test actual connectivity to mail servers to verify they're accepting connections.
⥠Response Times
Measure mail server response times to identify performance issues.
đ Deliverability Score
Overall assessment of email configuration and delivery capability.
Understanding Results
â Healthy Configuration
Multiple MX records with working SMTP servers and reasonable response times.
â ī¸ Needs Attention
Some mail servers not responding or single point of failure detected.
â Critical Issues
No working mail servers found or MX records missing/invalid.
Best Practices
- Use multiple MX records for redundancy
- Set appropriate priority values (10, 20, 30)
- Ensure all MX servers are functioning
- Use fully qualified domain names (FQDN)
- Avoid pointing MX to CNAME records
- Monitor mail server availability regularly
MX Priority Guide
Primary Server
Server: mail.example.com
Lowest priority number = highest priority. This server receives all email traffic first.
Backup Server
Server: mail2.example.com
Used when primary server is unavailable. Provides redundancy and reliability.
Tertiary Server
Server: mail3.example.com
Additional backup server for maximum uptime. Optional but recommended for critical domains.
Common Issues & Solutions
No MX Records Found
Cause: Domain has no MX records configured in DNS.
Solution: Add MX records pointing to your mail server in your DNS settings.
Mail Server Not Responding
Cause: Server is down, firewall blocking, or wrong hostname.
Solution: Check server status, verify hostname, and test network connectivity.
Single Point of Failure
Cause: Only one MX record configured.
Solution: Add backup MX records with higher priority numbers for redundancy.
Frequently Asked Questions
What are MX records?
MX (Mail Exchange) records are DNS entries that specify which mail servers handle email delivery for a domain. They include priority values to determine the order in which servers should be contacted.
Why check MX records?
Checking MX records helps verify email configuration, troubleshoot delivery issues, ensure redundancy with backup servers, and confirm that emails can be delivered to your domain.
What does MX record priority mean?
MX priority determines the order mail servers are contacted. Lower numbers have higher priority. If the primary server (lowest number) is unavailable, mail is routed to the next priority server.
How many MX records should I have?
At least one MX record is required for email delivery. Multiple MX records provide redundancy - if the primary server fails, email is delivered to backup servers. 2-3 MX records are common.
Why is SMTP testing important?
SMTP testing verifies that MX records point to working mail servers. A domain can have correct MX records but non-functional mail servers, preventing email delivery.
What causes MX record issues?
Common issues: missing MX records, wrong server hostnames, unreachable mail servers, DNS propagation delays, misconfigured priorities, or pointing to non-existent servers.