365 mx record co uk.mail.protection.outlook

A MX record!

The MX record you provided is:

365 mx record co.uk.mail.protection.outlook

Let's break it down:

• 365: This is likely a reference to Microsoft 365, a cloud-based productivity suite that includes email services.
• mx record: This is a type of DNS record that specifies the mail server responsible for accepting email messages on behalf of a domain.
• co.uk: This is the top-level domain (TLD) for the United Kingdom.
• mail.protection.outlook: This is the hostname of the mail server responsible for accepting email messages for the co.uk domain.

In other words, this MX record is telling the world that the mail server responsible for accepting email messages for the co.uk domain is located at mail.protection.outlook, which is likely a Microsoft 365 mail server.

When an email client or server wants to send an email to a user with a co.uk email address, it will look up this MX record and use the specified mail server to deliver the email.