Username @ Hostname. domain name
Suppose the user name you apply for is 12345, and the common email address can be expressed as follows:
QQ e-mail: 12345@qq.com, you can register your application by opening the webpage in mail.qq.com;
Netease e-mail: 12345@ 163.com or 12345 @ 126.com Open the webpage at mail. 163.com, you can register your application, and then select Yes.
Google Mail: 12345@gmail.com, but this server is abroad, so mainland users can't register to surf the Internet.
Company e-mail: this is generally hired by a company or unit and issued by the company.
Above, you can register and fill in according to your needs.