If you want to export Zimbra to Gmail then you can try any profitable application like KDETools Zimbra to Gmail Converter.
• Zimbra Converter is safe tool which can proficiently import Zimbra file to Gmail and additional file format such as PST, MBOX, EML, EMLX, HTML, PDF and etc.
• This tool also directly import Zimbra to Office 365 and Exchange Server account.
• This application shows free preview of the data before the migration process.
• This application easily import Zimbra file to Gmail, G Suit, Google Drive and etc.
• This tool maintain folder Structure during the conversion process.
Read more: https://www.kdetools.com/zimbra/gmail/