If you need to move TGZ data files of Zimbra into Outlook PST and need an easy & simple solution without losing any data from the files. Then I will refer you this Vartika Zimbra to PST conversion solution article. The option is one of the best for Zimbra TGZ to PST Conversion method. I also used this solution and it provides the multiple techniques and helps to migrate the data with an accurate and hassle-free manner.
Export PST to an outlook from Zimbra Emails
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.