The EmailProHelp PST Splitter will easily split large PST files above 50 GB into smaller PST files. his software even converts OST files to MBOX, EML, EMLX, PDF, PST, MSG, and YAHOO. The software will convert Multiple OST Files to PST at Once. You can add Large-sized OST files of more than 50 GBs for conversion, It also runs smoothly on Windows, 10, 8.1, 8, 7, Vista, XP, and below versions. Converts and transfers Emails, Contacts, Calendars, Notes, Journals, etc. from PST to PST.