MX Records, or Mail Exchange Records, are a type of DNS (Domain Name System) record used to direct email messages to the correct mail servers. They specify which server should handle incoming emails for a domain, ensuring that messages reach their intended destination. Each MX Record has a priority value, which determines the order in which mail servers are used. If the primary server is unavailable, the next server in line, based on priority, will receive the email. This system helps maintain reliable email delivery and ensures that messages are not lost.