Trim PST File - Version 4.0 Trim PST file to maintain the size of your PST file so that it won't cross the limit of 2GB which is the one of the major reasons for PST file corruption. The PST splitter software is capable of offering 4 different choices to Outlook users for splitting large PST files into various small portions. Now users can divide PST file or archive PST file as per size, date, year and folder. Software can be used in multiple ways to trim PST files size.