The primary public folder mailbox contains a writeable copy of the public folder hierarchy plus content and is the first public folder mailbox that you create for your organization. Subsequent public folder mailboxes will be secondary public folder mailboxes, which will contain a read-only copy of the hierarchy plus content.

For detailed steps, see Create a Public Folder Mailbox.

For detailed steps, see Create a Public Folder.

After you create the public folder, you’ll need to assign the Owner permissions level so that at least one user can access the public folder from the client and create subfolders. Any public folders created after this one will inherit the permissions of the parent public folder.

1. In the Exchange admin center (EAC), navigate to Public folders > Public folders.
   
   
2. In the list view, select the public folder.
   
   
3. In the details pane, under Folder permissions, click Manage.
   
   
4. In Public Folder Permissions, click Add .
   
   
5. Click Browse to select a user.
   
   
6. In the Permission level list, select a level. At least one user should be an Owner.
   
   
7. Click Save.
   
   
8. You can add multiple users by clicking Add and assigning the appropriate permissions using the steps above. You can also customize the permission level by selecting or clearing the check boxes. When you edit a predefined permission level such as Owner, the permission level will change to Custom.
   
   

For information about how to use the Shell to assign permissions to a public folder, see Add-PublicFolderClientPermission.

If you want users to send mail to the public folder, you can mail-enable it. This step is optional. If you don't mail-enable the public folder, users can post messages to the public folder by dragging items into it from within Outlook.

1. In the EAC, navigate to Public folders > Public folders.
   
   
2. In the list view, select the public folder you want to mail-enable.
   
   
3. In the details pane, under Mail settings – Disabled, click Enable.
   
   A warning displays asking if you are sure you want to enable mail for the public folder. Click Yes.
   
   

The public folder will be mail-enabled and the name of the public folder will become the alias of the public folder. If you have multiple recipients with that name, the public folder’s alias will be appended with a number. For example, if you have a distribution group named SalesTeam and you create a public folder named SalesTeam and then mail-enable it, the alias of that public folder will be SalesTeam1.

For information about how to use the Shell to mail-enable a public folder, see Enable-MailPublicFolder.