You can use this method to delete, deleted mail from delete/trash folder in Outlook. This will help keep your email server from getting full.
1. Select folder to delete from, typically your Deleted Items.
2. Right click the folder you would like to delete from and select Properties.
3. In the Properties dialog box, go to the AutoArchive tab and select your desired settings.
You may or may not get a warning to set Global Archiving.
4. To set Global settings for frequency, Select the File tab at the top of the screen and then Options.
5. Select Advanced on the lefthand menu and then click on AutoArchive Settings.
6. Choose how often you want to run AutoArchive, and whether you want to be prompted before it runs.
7. Leave all the other options deselected.
Click here to watch the demo video: www.myeasypconline.com/setting-up-outlook-to-auto-delete-deleted-items/