I was looking into transferring, migrating and importing some of my Microsoft Outlook .PST files / emails into Thunderbird which is on my Linux Ubuntu Desktop (Precise 12.04). Here are a few simple steps in getting it done.

These are the steps I followed for successfully importing mails from Outlook to Thunderbird.

1.Install Thunderbird.

apt-get install thunderbird

2. Install Readpst for converting pst to mbox.

apt-get install readpst

3. Convert Pst to Mbox using below command.

readpst -r Desktop/outlook.pst

(If your Outlook.pst is on desktop otherwise give proper path.)

4.Install Import/Export thunderbird addons

Click Here to download addons. or go through site.

5. Import converted Message.

Go to Tool>Import/ExportTools>Import Mbox File.

Now You Have successfully Imported Outlook messages to Mozilla Thunderbird .