You should TRY this MBox to PST Converter tool which is an excellent tool to select MBox/MBX email client, download and convert the same to Outlook PST. You can get the added flexibility with this tool to append the new data file to add to desired PST file. this tool Preview of email items before saving to Outlook PST file. this tool can Performs selective mailbox conversion into importable PST file directly and saved Converted mails in RTF, HTML, PDF and Office 365 and its to Allows creating new PST file or converting to current PST files. this tool can Supports MS Outlook 2007, 2010, 2013, 2016 and 2019. and Allows conversion of Entourage, Thunderbird, PocoMail, Spicebird, Mulberry, Eurora, Netscape, SeaMonkey, OperaMail, ClawsMail, MozillaMail, Cone, Evolution, Sylpheed, Gnu Mail and Mutt email clients.