How to migrate Zimbra to Office 365
If you want to migrate Zimbra to Office 365 account then you can try a third-party tool like Zimbra to Office 365 Converter. The software allows the user to migrate Zimbra file to Office 365 and Exchange server account. The tool maintains Zimbra items such as emails, contacts, calendar, notes, tasks, journals, and etc.
Read More: http://www.zimbra-converter.com/office-365/