How to Auto Empty Trash in Windows Mail or Outlook

Microsoft's three primary tools to help users manage their email all handle trashed emails similarly, but only the desktop Outlook program supports an option to auto-purge your deleted items.

The default mail client in Windows 10 uses per-account folder settings, so you'll have to delete your trash from each folder individually.

1. Select the Deleted Items folder for the email account. 
2. Enter Selection Mode by clicking the icon above the deleted-message list that looks like four lines prefixed with a pair of check marks.
3. Click the checkbox in front of the Deleted Items folder name, just above the message list. When you select it, all the messages should appear checked.
4. Click the trash can icon to permanently delete the message from your Deleted Items folder.

You cannot configure Windows Mail to automatically delete messages.

The online version of Microsoft's email service—now called Outlook.com, but formerly called Hotmail—deletes messages to a Deleted Items folder.

1. Right-click on the Deleted Items folder.
2. Click Delete All from the context menu.

You cannot configure Outlook.com to automatically delete messages.

The desktop version of Microsoft's email program stores trash in a Deleted Items folder for each attached account. As with Windows Mail, you'll need to handle these on a per-account basis if you've connected more than one email account to Outlook.

1. Right-click on the Deleted Items folder for the email account.
2. Click Empty Folder from the context menu.

The desktop client does support a universal auto-removal of deleted items. To activate it:

1. Click File | Options.
2. Click Advanced.
3. In the section titled "Outlook start and exit," activate the checkbox next to the option that says "Empty Deleted Items folders when exiting Outlook."
4. Click OK.