Outlook Express (Windows XP)

1. Open Outlook Express.
2. Go to the Tools menu and select Options
3. Click Maintenance tab.
4. Check Empty deleted items
5. Check Purge deleted messages
6. Click OK.
7. Go to your ArtSci inbox and remove any unneeded messages
8. Go to the Edit menu
9. Select Purge Deleted Messages
10. Do this for other ArtSci mail folders.

Windows Mail (Windows Vista)

1. Open Windows Mail
2. To automatically purge deleted messages from your IMAP e‑mail account, click the Tools menu
3. Click Options
4. Click the Advanced tab
5. Click Maintenance, and then click Purge Deleted Items when leaving IMAP folders
6. Go to the Edit menu, and then click Purge Deleted Messages
7. Do this for other ArtSci mail folders. 

Outlook 2003

1. Open Outlook
2. In your ArtSci inbox, remove any unneeded emails
3. Go to the Edit menu
4. Select Purge Delete Messages
5. Follow these same steps for other mail folders

Outlook 2007

1. Open Outlook
2. In your ArtSci inbox, remove any unneeded emails
3. Go to the Edit menu
4. Select Purge
5. Choose one of these options: Purge Marked Items in "folder" (Only items marked for deletion in the folder you are in are purged), Purge Marked Items in "e-mail account" (All items marked for deletion in any folder for this e-mail account are purged), Purged Marked Items in All Accounts (All items marked for deletion in any folder for all accounts listed are purged)