I would like to suggest an automated tool to migrate Zimbra to Office 365. This software safely migrate Zimbra to Office 365 and Exchange Server account. The software maintains folder structure and metadata of email during the migration process. The application migrate Zimbra to different file formats such as PST, EML, EMLX, HTML, MSG and MBOX etc.

Know more info- https://www.vartikasoftware.com/fr/zimbra-to-outlook-migrator.html#