Error when you try to add an Address (A) or CNAME record in Office 365 Small Business: "Another DNS record already exists with this host name"

PROBLEM

In Office 365 Small Business, you try to add an Address (A) record or a CNAME record in the Office 365 portal. However, you get the following error message:
Another DNS record already exists with this host name. Type a different name.

SOLUTION

To resolve this issue, do one of the following, as appropriate for your situation.

Add a record other than a www record

To add a record other than a www record, use a different host name, or update the existing record.

Add a www record that points to a website that's hosted by a third-party

For more information about how to add a www record that points to a website that's hosted by a third-party, go to the following Microsoft website:
Update DNS records to keep your website with your current hosting provider

MORE INFORMATION

This issue occurs if the DNS record already exists.

Still need help? Go to Microsoft Community.