When we start facing space issue in Outlook, we create an Outlook Data file (.pst) or .PST file. Once we create a Outlook Data File folder, we can move emails to that folder. It will free up the space on an email server.
.PST file in Outlook
To create an Outlook Data file (.pst), we need to perform 3 simple steps:
Step 1. Open Outlook and go to Home ribbon.
Step 2. Click on New Items > More Items > Outlook Data File.
Step 3. Click Ok to create a data file. Give name and select location for the file to be saved.
Now, the folder can be located on the left side of your mailbox, below inbox or sent items. You can drag and drop any email to this folder. This will free up the space one email server and your mailbox will work flawless.