You will probably have followed a zillion links before you got to this page and the only reason I am blogging about it is because most of these links will provide you with useless information or point you to software which will only export the first few files.
If you, like I, have collected thousands of emails in your trusted .pst folders on Microsoft Outlook and you (like I) are moving to another platform such as Apple, you will quickly notice that taking your mail with you is not such an easy thing.The easiest route could be through Outlook express. But installing that becomes more and more difficult and it does not handle .pst files that are stored on disk.
Right click the folder “Outlook Import” that you just imported and export everything in mbox format including a nifty directory structure.
- Importing Email into Mozilla Thunderbird (brighthub.com)