PST Split Software - Version 2.2 Your Outlook not working properly reason might be oversized PST file. Do you want .PST split file tool? To overcome your problem this is best PST split tool. Large size PST creates problem in Outlook like slow processing. What you need to do is just split PST into smaller files.PST split software not only allow user to increase the processing speed it also allows user to maintain the data, means if user want to access some data from a specific date, some specific size or from some specific year. PST split software gives you the option to maintain your data according to the above mention way or we can say that PST split files in following way:• PST split size.• PST split date.• PST split year.