Take QQ mailbox as an example:

The general format of qq mailbox is: qq number@qq.com. For example, the qq number is 12345678, then the qq mailbox is: 12345678@qq.com.

vip mailbox format: @vip.qq.com is a new email address provided by QQ mailbox, that is, a new address is added to the existing QQ mailbox. Together with the domain name of @qq.com, a QQ mailbox can have two domain names.

vip mailbox:

Overview: @vip.qq.com is a new email address provided by QQ mailbox, that is, a new address is added to the existing QQ mailbox. Together with the domain name of @qq.com, a QQ mailbox can have two domain names.

Acquisition: You need to pay to activate QQ membership service before you can register it. After registration, the domain name cannot be changed, and you can continue to use it after the QQ membership service expires.

Features: The original email address is still available, and multiple addresses can use the same email address.

Function: Compared with previously launched domain names, there is no functional difference (for example, the mailbox size will not change).