DNS MX Record Lookup - Check Email Server Configuration
Look up MX records for any domain to identify mail servers and their priorities. Essential for troubleshooting email delivery issues and verifying email setup.
Understanding This Tool
What It Does
Look up MX (Mail Exchange) records for any domain to identify the mail servers responsible for handling email. This tool is essential for understanding email infrastructure and delivery.
Understanding the Results
- MX Records: List of mail servers for the domain
- Priority: Numerical priority (lower = higher priority) for mail delivery
- Mail Server: Hostname of each mail server
- IP Address: The resolved IP of the mail server
- TTL: Cache duration for the MX record
Common Use Cases
- Email Setup: Verify MX records are configured correctly after mail server changes
- Email Troubleshooting: Diagnose email delivery issues by checking MX records
- Provider Verification: Confirm which email service a domain uses
- Migration Planning: Identify current email infrastructure before switching providers
- SPF/DKIM Setup: Understand the mail servers when configuring authentication
Pro Tips & Best Practices
- Multiple MX Records: Multiple servers provide redundancy for email delivery
- Priority Order: Mail servers are tried in priority order if the primary is down
- Migration Window: Update MX records and monitor delivery during transitions
Frequently Asked Questions
MX (Mail Exchange) records tell email servers where to deliver mail for your domain. They point to mail server hostnames and include priority values for fallback servers.
Lower priority numbers mean higher preference. Mail servers try the lowest number first (e.g., priority 10 before priority 20). Same priority means load balancing between servers.
At least 2 for redundancy. Primary server handles most mail, secondary acts as backup if primary is down. Large organizations may have 3-5 for better reliability and load distribution.
Check: MX records point to valid A records, mail server is running and accepting connections on port 25, SPF/DKIM/DMARC are configured, domain isn't blacklisted, and firewall allows SMTP.
No, MX records must point to hostnames (A records or CNAMEs that resolve to A records). Pointing directly to IPs violates RFC specifications and won't work.
It's recommended to have a null MX record (priority 0, hostname '.') to explicitly indicate no mail is accepted, preventing backscatter and reducing spam targeting your domain.
Frequently Asked Questions
What are MX records?
MX (Mail Exchange) records tell email servers where to deliver mail for your domain. They point to mail server hostnames and include priority values for fallback servers.
What do MX record priority numbers mean?
Lower priority numbers mean higher preference. Mail servers try the lowest number first (e.g., priority 10 before priority 20). Same priority means load balancing between servers.
How many MX records should I have?
At least 2 for redundancy. Primary server handles most mail, secondary acts as backup if primary is down. Large organizations may have 3-5 for better reliability and load distribution.
Why isn't my email working if MX records look correct?
Check: MX records point to valid A records, mail server is running and accepting connections on port 25, SPF/DKIM/DMARC are configured, domain isn't blacklisted, and firewall allows SMTP.
Can MX records point to IP addresses?
No, MX records must point to hostnames (A records or CNAMEs that resolve to A records). Pointing directly to IPs violates RFC specifications and won't work.
Do I need MX records if I don't have email?
It's recommended to have a null MX record (priority 0, hostname '.') to explicitly indicate no mail is accepted, preventing backscatter and reducing spam targeting your domain.
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How this tool works: This tool runs in your browser and on our server in real time. Depending on the tool, results are computed directly from the input you provide or retrieved from live, authoritative data sources at the moment you run a lookup. We do not sell your data, and your lookups are kept private — any history shown here is stored only on your device.