Try Zimbra to PST Converter works well for all the latest versions of Microsoft Outlook and Windows. This application supports to keep HTML format of Meta properties, embedded image, Attachment etc. Some more features such as the fast conversion of data, the Corrupted file also converted safely, etc.
Export PST to an outlook from Zimbra Emails manually
Select the file tab and choose Open & Export.
Select the Import/Export tab. Import and Export Wizard will appear.
Then select the Outlook data file option.
Select the Zimbra backup files folder.
Click the Browse button to save the file.
Check the PST file where you saved it.