The process of exporting email from Outlook to Thunderbird on Windows is really easy. Exporting it from Thunderbird and importing in to Outlook is not hard either, just time consuming. Both ways can be done.
Outlook to Thunderbird
This is actually really easy. The first thing you need is all your email in Outlook. Then, when you setup Thunderbird it will ask you if you want to import your Outlook email. Say yes and it does all the work. No, Thunderbird doesn’t have an import function for the PST file, but it can import anything that’s in Outlook on the same machine. It’s as easy as that.
Thunderbird to Outlook
This process is a bit more complex . Outlook doesn’t directly import Thunderbirds email, however with the right tools, and some time, it can be done.
The first thing you’ll need is a program called IMAPSize. It’s a free Windows application that has a built in tool called mbox2eml. This handy program is used to convert Thunderbird’s mbox email files into eml files. The mbox files are found in your Thunderbirds profile folder (usually in the mail -> local folders). If you don’t see any files with the extension mbox, then it’s the ones without an extension.
The downside here is that each folder you have in Thunderbird is a seperate mbox file. You have to convert each one. Anything in a sub folder will have to be converted too and you may start to loose your folder structure. Oh well, you can always put it back together later.
Once everything is in eml format, you must now startup Outlook Express! That’s right, Express. No need to setup an email account in there, but you should setup all your folders to mirror what you had in Thunderbird. Then, open the folders on your computer that were created from the mbox2email tool and drag the individual eml files into the corresponding Outlook Express folders. You can drag and drop as many eml files as you want, but you can’t drag in a folder. Once you’ve copied all your emails into Outlook Express, you can now import them into Outlook.
Startup Outlook, create your profile and once that’s all setup, go to Import/Export, import from another application and choose Outlook Express. If I remember correctly, it first said it couldn’t import the email then it asked me if I wanted to import all the email. I said yes and all the folders and emails were imported into Outlook.
So there you have it. Importing email from Outlook to Thunderbird is pretty simple and importing email from Thunderbird to Outlook can be done. Depending on how many emails and folders you have will determine how much time it will take. Defiantly going from Outlook to Thunderbird is easier and quicker!
For a much more detailed process of moving from Thunderbird to Outlook, check out this great tutorial: Export Thunderbird to Outlook.