The Sysinfo PST merge tool merges your small PST Files into one. The tool provides you an option to merge Outlook Contacts, Emails, Calendars, journals, and other mail items into a single file. The tool has an option to remove duplicate items from the chosen PST files. Combine multiple Outlook data files with emails, contacts, calendars, tasks, etc. It offers three advanced options to merge multiple PST files into one PST. Have an option to remove duplicate items from the chosen PST files.