You can release a domain name to unbind it from your mailbox when you do not plan to attach a new one.
Back up your emails before you release the domain name.
After you release the domain name, you cannot log on at mail.your_domain_name. Instead, you can log on at https://qiye.aliyun.com.
After you release the domain name, the mailbox cannot send or receive emails. If you still need to use email, you must replace the released domain name with a valid one. For more information, see Replace the domain name attached to Alibaba Mail.
Release a domain name
1. Log on to the Alibaba Cloud Management Console, and then click Manage > Basic Information > Replace Domain Name.
2. A prompt appears with the message: If you do not plan to use this mailbox anymore, you can release the domain name. Click Release Domain Name.
3. Click Submit.
The system generates and attaches a new domain name. You must back up your mailbox data promptly. The new domain name uses the following naming convention: "release-bind-your_domain_name".