Issue: You have large pst file of the outlook. You delete mails from pst but the .pst (personal folder file) file size still does not reduces.
Solution: Open your Outlook and follow the below steps. This may take several minutes depending upon the size of your pst file
1. On the File menu, click Data File Management.
2. Click the data file that you want to compact, and then click Settings.
3. Click Compact Now.