To convert PST to MBOX manually, you can follow these steps:
Step 1: Export Emails from Outlook PST
Open Microsoft Outlook on your computer.
Click on "File" in the top menu bar.
Select "Options" from the drop-down menu.
In the Outlook Options window, click on "Advanced" in the left-hand pane.
Scroll down to the "Export" category and click on "Export" button.
In the Import and Export Wizard window, select "Export to a file" and click on "Next".
Choose "Microsoft Exchange" as the file type and click on "Next".
Select the PST file you want to export and choose a location to save the exported file. Click on "Finish" to start the export process.
Step 2: Install Mozilla Thunderbird
Download and install Mozilla Thunderbird, which is a popular email client that supports MBOX format.
Step 3: Import PST File to Thunderbird
Open Mozilla Thunderbird on your computer.
If you are setting up Thunderbird for the first time, you will be prompted to create an email account. You can skip this step if you don't want to set up an email account.
Click on "Tools" in the top menu bar and select "Import" from the drop-down menu.
In the Import window, select "Mail" and click on "Next".
Choose "Outlook" as the type of mail you want to import and click on "Next".
Click on "Browse" and locate the PST file you exported from Outlook in Step 1.
Select the folders you want to import and click on "Next".
Choose the destination folder in Thunderbird where you want to import the PST data and click on "Next".
Click on "Finish" to start the import process.
Step 4: Export MBOX Files from Thunderbird
In Mozilla Thunderbird, select the folder where you imported the PST data.
Click on "Tools" in the top menu bar and select "Export" from the drop-down menu.
Choose the folder you want to export as MBOX format and click on "Next".
Choose a location to save the MBOX file and click on "Finish" to start the export process.
After following these steps, you should have successfully converted your PST file to MBOX format manually using Microsoft Outlook and Mozilla Thunderbird.
Greetings,
Peter