Hey, if you are looking for the best tool to convert OST files to PST then I would like to suggest the brilliant OST Converter for Mac Tool by MacMister. It can easily convert multiple OST files into PST along with attachments and other email details. One can try the demo edition of the program which allows to import only 25 OST files to PST format without any cost.

For More Information: https://www.macmister.com/blog/import-ost-file-to-outlook-pst/

I suggest you to try CubexSoft OST to PST Converter for Mac & Windows software that is very helpful tool for best information and get my all data emails back with complete items of OST Mailbox to multiple file formats such as PST, PDF, MBOX, EML, MSG, DOC, OLM, Zimbra, Office 365, etc.
Check out – https://www.cubexsoft.com/ost/
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