MX record checker

An MX (Mail Exchanger) record is a DNS record that specifies which mail servers are responsible for receiving email for a domain. When someone sends an email to you@yourdomain.com, the sending mail server looks up the MX records for yourdomain.com to find where to deliver the message.

The priority number (also called preference) tells senders which mail server to try first. Lower numbers = higher priority. A server with priority 10 is tried before one with priority 20. If the primary server is unavailable, senders retry with the next highest priority server. Equal priority values means senders choose randomly — this is sometimes used for load balancing.

It's strongly recommended. A single MX record means email will bounce or queue during any outage. Adding a secondary MX (typically your mail provider's backup server, or a service like Google MX backup) ensures email is accepted even if your primary server is temporarily down.

Several reasons: the mail server the MX points to may be down or unreachable on port 25; your IP or domain may be on a blacklist; SPF, DKIM, or DMARC might be misconfigured causing rejection; or the receiving server may be filtering based on content. MX records are just the first step — authentication records and reputation matter too.

Yes, with care. Lower your TTL to 300 seconds a day before making changes so the change propagates quickly. Add the new MX records before removing the old ones. Wait for propagation (typically 5–30 minutes with a low TTL), confirm the new server is receiving, then remove the old records and restore your TTL.