MX Record Lookup

MX (Mail Exchange) records are DNS entries that specify which mail servers are responsible for receiving email on behalf of your domain. Without MX records, your domain cannot receive email. They're essential for email delivery and are checked by sending mail servers to determine where to route messages.

MX priority determines the order in which mail servers are tried. LOWER numbers = HIGHER priority. For example, priority 10 is tried before priority 20. If the highest priority server (lowest number) is unavailable, the sending server tries the next priority level. This provides failover and redundancy for email delivery.

SPF (Sender Policy Framework) is a DNS TXT record that specifies which mail servers are authorized to send email on behalf of your domain. It helps prevent email spoofing and improves deliverability by allowing receiving servers to verify that incoming mail from your domain comes from authorized servers. Format: 'v=spf1 include:_spf.google.com ~all'

DMARC (Domain-based Message Authentication, Reporting and Conformance) is a DNS TXT record at _dmarc.yourdomain.com that tells receiving servers what to do with emails that fail SPF/DKIM checks. It prevents email spoofing and phishing by specifying policies (none, quarantine, reject) and provides reporting on email authentication failures.

This means your domain doesn't have MX records configured in DNS, so it cannot receive email. To fix this: 1) Log into your DNS provider (domain registrar or hosting), 2) Add MX records pointing to your mail server, 3) Wait 1-48 hours for DNS propagation. If you use Gmail/Microsoft 365, consult their documentation for correct MX records.

Yes, best practice is to have at least 2-3 MX records for redundancy. If your primary mail server (lowest priority number) goes down, email will automatically be routed to the backup servers. For example, Google Workspace uses 5 MX records with priorities 1, 5, 5, 10, and 10 for high availability.

Use this MX lookup tool to check: 1) MX records exist and resolve to mail servers, 2) Each MX hostname resolves to valid IP addresses, 3) SPF record is present and includes your mail provider, 4) DMARC record is configured with appropriate policy. Test by sending email to and from your domain.

Common errors: 1) Pointing MX to an IP address instead of hostname (must be hostname), 2) Forgetting trailing dot in some DNS systems, 3) Using same priority for all records (defeats redundancy), 4) Not updating MX records when changing email providers, 5) Typos in hostnames, 6) Not waiting for DNS propagation (up to 48 hours).

Gmail/Google Workspace provides 5 geographically distributed MX records with automatic failover, spam filtering, and 99.9% uptime SLA. Custom mail servers give you full control but require maintenance, security patches, spam filtering setup, and redundant infrastructure. For most businesses, hosted email (Gmail, Microsoft 365) is more reliable and cost-effective.

DNS changes typically propagate within 1-4 hours, but can take up to 48 hours globally. Factors affecting speed: TTL (Time To Live) of old records, DNS provider infrastructure, ISP DNS caching. You can reduce propagation time by lowering TTL before making changes (e.g., to 300 seconds), making the change, then raising TTL back to normal (3600-86400 seconds).