The best method for importing OLM files to Outlook PST file is to use a wonderful application i.e. BitData Migration OLM to PST Converter. It also moves any size of OLM files into multiple formats such as PDF, EML, MSG, DOC, MBOX, ICS, CSV, vCard, Gmail, IMAP, Office 365, Thunderbird, Zimbra, etc. Also, it’s effortlessly run on all versions of Outlook, macOS, and Windows OS.