MX Lookup

よくあるご質問

What is a DNS MX record?

An MX record or mail exchange record, is a type of DNS record that specifies which mail servers are responsible for accepting email messages for a domain. They are essential for email delivery, as they direct incoming emails to the correct servers depending on the email service provider (e.g., Google Workspace, Microsoft 365, Zoho Mail, etc.). A domain can have multiple MX records, each with a different “priority” value.

How does an MX record work?

When an email is sent, the sender’s mail server doesn’t know where to deliver it, so it queries the DNS for the recipient’s domain name (e.g., gmail.com) to find its MX record. The authoritative DNS server for that domain responds with a list of designated mail servers, each accompanied by a numerical priority value.

The sending mail server then attempts to connect to the recipient's mail server with the lowest priority number first (actually the highest priority value). If the server is unavailable, it systematically tries the next lowest-priority server until a connection is established. This system of multiple records with priorities ensures that email can still be delivered even if one mail server is down.

Why is an MX record lookup important?

Checking a domain’s MX record is essential because an MX record enables reliable email delivery. It helps detect and prevent misconfigurations that could prevent users from receiving emails.

Who controls my MX record?

The domain owner has control over MX records, but they are managed through interfaces provided by the DNS hosting service provider.

ドメイン名の他のDNSレコードはどうすれば確認できますか？

You may use DNS Lookup API or our lookup tool, which returns TXT, NS, and other DNS record types. If you only want to look up a specific record type, you can use these tools for free:

• CNAME Lookup tool
• TXT Lookup tool.