How to Convert PST Files to MBOX Format?

[Davidson671]

Hi everyone, I have several PST files exported from Outlook, and I want to access them in Thunderbird. Can anyone suggest a reliable PST Converter tool that supports PST to MBOX conversion without data loss?

[a_aleinikov]

Hi @Davidson671 ,

Yes, to open your Outlook PST files in Thunderbird, you'll need a reliable PST to MBOX converter. Since Thunderbird uses MBOX format, direct importing of PST isn’t supported without conversion.

Here are some tools that users often find helpful:

1. SysTools PST Converter – Paid, user-friendly, supports batch PST to MBOX with attachments.

2. Aryson PST Converter – Another reliable option with preview and selective export features.

3. Softaken PST to MBOX Converter – Simple interface, handles large files well.

4. MailStore Home – Free (for personal use), supports exporting Outlook data to various formats including MBOX.

5. Thunderbird with Add-ons – You can try using the ImportExportTools NG add-on if you can first import the PST into Outlook and export to EML, then import EML into Thunderbird.

There’s no 100% free and direct PST-to-MBOX tool that preserves full structure, especially for large or complex mailboxes. Most professional tools are paid.