You can set Outlook to automatically delete spam messages older than a certain date.
Outlook Method 1:
Spam Bully menu > Configure Spam Bully > Delete Spam option
Check the box "Remove spam older than"
Then select the number of days from the slider that you want to keep your spam messages.
Outlook Method 2:
Right click on the "Spam" folder.
Select "Properties"
Select the "Auto Archive" tab.
Select "Archive this folder using these settings."
Select the amount of time that you want to keep your spam messages.
Click "Permanently delete old items" or you can auto archive them if you prefer to save your spam messages.
Click Apply.
Outlook Express Method 1:
Currently Outlook Express can only be set to delete all spam messages on each close.
Spam Bully menu > Configure Spam Bully > Delete Spam option
Select "Move spam to Deleted Items folder"
Then in outlook Express Go to Tools > Options > Maintenance tab
Check "Empty messages from 'Deleted Items' folder on exit".
Outlook Express Method 2:
Modify the Spam Bully message rule.
Go to the Tools menu > Message Rules > Mail
Modify the "Spam Bully Filter" rule
Change the rule action from "Move it to the specified folder" to "Delete it"