When you add a CNAME record, it may conflict with an A or MX record.

The CNAME record conflicts with an A record

You must delete the A record before you can add a CNAME record. The deletion of the A record will not affect the website services because the CNAME record will redirect user requests to CDN edge nodes where resources are retrieved from the origin server. For more information about how a CNAME record works, see How it works.

The CNAME record conflicts with an MX record

To address this issue, you can enable URL redirection. Make sure that both the source and destination domain names have a valid Internet Content Provider (ICP) number. The following table describes how to configure URL redirection.

Record settings:
Record Type Host ISP line Record Value TTL
URL @ Default example.com 10 minutes
MX @ Default demo.aliyundoc.com 10 minutes