To move free MBOX files to Office 365, I strongly suggest using the SysInspire MBOX Converter tool. It is one of the most capable tools for converting single and numerous MBOX files to PST files. It can extract sections of Thunderbird MBOX files to PST files without losing data. Web scanners and antiviruses have thoroughly examined this software.
Read More:- Convert MBOX to PST
Converting mail from MBOX to PST is similar to importing MBOX in Outlook, but it provides several advantages: When converting MBOX to PST, the converter uses existing or new PST files. Importing messages to Outlook requires existing mailboxes, PST data files, or Exchange Server Public Folders.