If you want to transfer Zimbra to Gmail account then yo can try commercial solution like Zimbra to Gmail Converter tool to transfer Zimbra to Gmail, G Suite, Google Drive and etc. With this tool, you can also transfer Zimbra to PST, MSG, EML, HTML and PDF file format without any problem. The application makes it easy for the users to transfer Zimbra to Gmail without any data loss and security issues. Read more: https://www.kdetools.com/zimbra/gmail/
