I would like to suggest commercial solution like Zimbra to Office 365 Converter Software. This tool gives you a faster process to export Zimbra file to Office 365 and Exchange Server. This software export Zimbra items such as emails, appointments, contacts, tasks list, journals, notes, and etc. This application export Zimbra file to Office 365 and multiple file-formats including EML, MSG, EMLX, vCard, vCal, an etc.

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