refactor(frontend): unify mailbox terminology

Closes #1129

vitepress-docs/docs/en/guide/config-send-mail.md

@@ -150,19 +150,20 @@ cd worker
 wrangler secret put SMTP_CONFIG
 ```
 
-## User Accounts, Email Addresses, and Send Permission
+## User Accounts, Mailboxes, Email Addresses, and Send Permission
 
 These concepts are related, but they identify different objects:
 
 | Concept | Description |
 |---------|-------------|
-| User account | Signs in to the user center and can bind and manage multiple email addresses. The user account's login email is not automatically a sending or receiving address |
-| Email address | The identity that actually receives and sends mail, such as `name@example.com`. The address currently selected on the frontend home page is authenticated by its Address JWT |
+| User account | Signs in to the user center and can link and manage multiple mailboxes. The account email is not automatically a sending or receiving address |
+| Mailbox | The user-facing object that contains an inbox, sent mail, sending capability, and mailbox settings |
+| Email address | The concrete value that identifies a mailbox, such as `name@example.com`. The current mailbox is authenticated by its Address JWT |
 | Send permission and balance | Permission and balance records in `address_sender` are managed independently **per email address**; user roles configured by `NO_LIMIT_SEND_ROLE` can bypass address balance checks |
 
 Multiple email addresses bound to the same user account therefore do not share send permission or balance. To request permission for an address:
 
-1. Switch to the email address that needs to send mail
+1. Switch to the mailbox that needs to send mail
 2. Open the **Send Mail** page
 3. Click **Request Access**
 

vitepress-docs/docs/en/guide/feature/admin.md

@@ -4,31 +4,31 @@
 > You need to configure `ADMIN_PASSWORDS` or `ADMIN_USER_ROLE` to access the admin console
 > Admin role configuration: if the user role equals ADMIN_USER_ROLE, they can access the admin console
 
-After deploying the frontend application, click the upper-left logo 5 times or visit the `/admin` path to enter the management console.
+After deploying the frontend application, click the upper-left logo 5 times or visit the `/admin` path to enter the Admin Console.
 
 You need to configure `ADMIN_PASSWORDS` in the backend or ensure the current user role is `ADMIN_USER_ROLE`, otherwise access to the console will be denied.
 
 ## Admin Passwords vs User Accounts
 
-`ADMIN_PASSWORDS` is the management password for the Admin console. It is not a site user account
-and does not correspond to any mailbox address. Logging in with an admin password grants access to
+`ADMIN_PASSWORDS` is the password for the Admin Console. It is not a site user account
+and does not correspond to any mailbox. Logging in with an admin password grants access to
 the console, but that login itself cannot receive mail.
 
 Site user accounts are stored in the `users` table and use the user login flow. Whether a user can
-receive mail depends on whether they created or bound a mailbox address. Creating a normal user
-whose email looks like `admin@example.com` does not automatically grant admin permissions.
+receive mail depends on whether they created or bound a mailbox. Creating a normal user
+whose account email is `admin@example.com` does not automatically grant admin permissions.
 
 If you want a user account to access the Admin console, configure `ADMIN_USER_ROLE` and assign the
 same role to that user in user management.
 
 ![admin](/feature/admin.png)
 
-## Account List Sorting
+## Mailbox List Sorting
 
-The Accounts tab in the admin console supports column sorting. Click the column header to toggle ascending/descending order for:
+**Admin Console → Mailbox Management → Mailboxes** supports column sorting. Click a column header to toggle ascending/descending order for:
 
 - ID
-- Name
+- Email Address
 - Created At
 - Updated At
 - Mail Count