How to Import PST File to Thunderbird in 2026?

If you're switching from Outlook to Thunderbird, you might wonder how to import PST files. Unfortunately, Thunderbird does not support direct PST import, especially in the latest versions.

But don’t worry—there are simple workarounds you can follow.

Why Direct Import Doesn’t Work?

PST is a proprietary Outlook format, while Thunderbird supports MBOX format. That’s why you need an intermediate step.

Method 1: Using Outlook (Limited & Outdated)

This method works only in older Thunderbird versions:

1. Set Outlook as the default email client
2. Open Thunderbird
3. Go to Tools → Import → Mail
4. Select Outlook and import data

Limitation:

• Works only with older Thunderbird versions
• Requires Outlook installation
• Imports emails only (not full data)

Method 2: Convert PST to MBOX (Recommended in 2026)

This is the most reliable and widely used method.

Steps:

1. Convert PST file into MBOX format
2. Open Thunderbird
3. Import the MBOX file using ImportExportTools NG add-on

Why this works:

• Thunderbird fully supports MBOX files
• Ensures better data accuracy and structure

Suggested Solution: Cigati PST Converter

For a smooth and accurate migration, you can use Cigati PST Converter.

Key Benefits:

• Converts PST to MBOX format easily
• Supports bulk PST file conversion
• Maintains folder hierarchy and attachments
• No need to install Outlook
• User-friendly interface for beginners

In 2026, the best way to import PST into Thunderbird is by converting PST to MBOX using a reliable tool. Manual methods are outdated and limited, while professional tools ensure fast and secure migration.