I would like to recommend you secure application Zimbra to Exchange Server Converter Utility Tool to convert Zimbra file to Exchange Server file format.

Features

This application support multiple file formats such as PST, EML, EMLX, MBOX, etc

This application directly migrate Zimbra file to Office 365 and Exchange Server account.

This application also allows all MS Outlook version such as 2019, 2016, 2013, 2010, 2007, 2003 and etc.

Read more: https://www.kdetools.com/zimbra/exchange/