Try Zimbra to Exchange Server Converter tool simply convert Zimbra files to some file formats such as PST, MBOX, EML, EMLX, vCard, vCal, HTML, Office 365, etc. This conversion tool easily convert all Zimbra to Exchange Server account. This tool also has a feature to split files and convert them into parts, creating many small PST files without deleting or damaging the files.
Read More: https://www.kdetools.com/zimbra/exchange/