You can use this ToolsGround OST to PST Converter Software which is a very helpful tool for data transfer such as Tasks, Notes, Mail, Calendar, Contacts, etc. It supported all outlook version including 2003, 2007, 2010, 2013 and 2016, 2019 Outlook
version. It also converts OST files into various formats such as EMLX, HTML, MSG, VCF, MBOX and Office 365.
More Info:-
https://www.toolsground.com/ost-to-pst-converter/
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