Hi there, You can try the best tool to open multiple MBOX files in Outlook by just converting MBOX to PST format. The effortless and reliable Advik MBOX to PST Converter can easily convert MBOX files of any size to PST files. The MBOX to PST conversion tool is completely safe and secure. Some individuals can convert MBOX files to PST files without the need for any technical support.
Learn More: https://www.adviksoft.com/blog/open-mbox-file-in-outlook-windows/