Importing an OST file into Zimbra Desktop manually can be a bit challenging, as Zimbra primarily works with the .TGZ format for importing data. An OST (Outlook Offline Storage Table) file is a proprietary format used by Microsoft Outlook for storing email data when connected to an Exchange server. To migrate data from an OST file to Zimbra Desktop, you'll need to follow a multi-step process:

Step 1: Convert OST to PST

Since Zimbra Desktop doesn't natively support OST files, you must first convert the OST file to PST (Outlook Personal Storage Table) format, which can be imported into Zimbra Desktop.

Download and install a reputable OST to PST converter tool if you don't have one already. There are several third-party tools available online for this purpose. Ensure you choose a trusted one.

Launch the OST to PST converter tool.

Select the OST file you want to convert.

Choose the PST as the output format for the conversion.

Click the "Convert" or "Start" button to begin the conversion process. The time required will depend on the size of your OST file.

Once the conversion is complete, locate and save the PST file in a location you can easily access.

Step 2: Import PST into Zimbra Desktop

Now that you have your data in PST format, you can proceed to import it into Zimbra Desktop.

Open Zimbra Desktop if it's not already running.

Click on "Preferences" in the upper-right corner of the Zimbra Desktop window.

Select "Import/Export" from the left-hand menu.

Choose "Import" to open the import wizard.

Select "Outlook (PST file)" as the source to import from.

Click "Next" to proceed.

Browse to the location of your PST file and select it.

Choose the Zimbra mailbox where you want to import the data. You can either import into an existing folder or create a new folder for the imported data.

Click "Next" to start the import process.

Review and confirm the import settings.

Click "Finish" to initiate the import.

Wait for the import process to complete. The time it takes will depend on the size of your PST file.

Once the import is finished, you should see your Outlook data in Zimbra Desktop.

Greetings,
Peter