How to change your retention period of junk emails in Outlook
This guide will help you change how long Outlook keep junk emails.
You must have a hosted Exchange account with Sherweb.
1. Right click on your Junk Email folder in Outlook (Outlook 2013 shown) and select Properties.
2. Click on the AutoArchive tab. Click the Archive this folder using these settings radio button.
Select a retention time next to the Clean out items older than [X] Months/Weeks/Days line.
Finally, click on the Permanently delete old items radio button and then click on OK.
All Hosted Exchange accounts with Sherweb.