Update to Lion Server v10.7.3 or later.
For user who have already logged into Webmail and are missing the default folders, you will need to manually create and assign the required folders.
- Log into the affected users webmail account
- Go to Settings.
- Select the Folders tab.
- Click the + button at the bottom of window.
- Create a folder named "Deleted Messages".
- Create a folder named "Sent Messages".
- Create a folder named "Junk".
- Create a folder named "Drafts".
- Click the Preferences tab, then Special Folders.
- In the Main Options, select the appropriate folder for the option from the pop-up menu.
- After assigning the folder to their main option, click Save.