It is possible to set a designated "cleaning" schedule for the following folders:
- Deleted Items
- Junk E-mail
- Sent Items
This is similar to configuring a POP account to automatically delete emails from the server after a set amount of time. To do so the client or administrator must be logged into the appropriate account > select Settings > and select Folder Auto-Clean. In the main content area, you can then choose to Override the default auto-clean settings. Once you've selected the the preferred option hit Save.
Next, you will need to set the Rules - Click + New Rule. To create a rule you must first select a folder to target, then set the Type (Size or Age) and finally select the desired folder size after auto-clean.
Once you have finished with your auto-clean preferences hit Save.