If you want to resolve missing email attachments after converting the EMLX file to PST. Then you can use a third-party tool like
DailySoft EMLX to PST Converter software. This is a trusted tool and it can handle attachment better. This is a reliable software to transfer EMLX files with all email attributes intact and unchanged. It \allows users the independently convert single or multiple EMLX files at once. There is no need to install MS Outlook, Apple Mail, or any other programs to export data. It provides exceptional control in users’ hands to get the desired results. It also provides a free demo edition before purchasing. Read more:
http://https://www.dailysoft.org/emlx/pst/