This is arguably one of the most tedious (not difficult — there’s a difference) tasks one has to go through when importing his/her Microsoft Outlook PSTs, or “personal folder files”. Don’t ask me how they arrived at the acronym, but as my good friend Em did a quick google to Wikipedia, PST stands for Personal Storage Table. (They say it’s an open file format, but why does the importing to Thunderbird strips off formatting and leaves some data missing? More on this later)

Coming from my previous post on how to setup Zimbra and Thunderbird, here’s the reason why Thunderbird should not be set as the default mail client during its installation. The Import tool in Thunderbird gets the email or address book(s) from the current default email application on your computer. It would not make sense if Thunderbird tried to import mail from itself right?

First off, you have to make sure that MS Outlook is your default email program. You do this by going to Start > Control Panel > Internet Options > Programs.

On the dropdown for E-mail, set it to Microsoft Outlook.

Next, open your MS Outlook.

At this point, I have to make a warning: If you have several PSTs to import, the process might take a long while to complete. If you have work to do, I suggest you do this after office hours. Or, alternatively, you might want to close your other PSTs and leave just one or two open on your current Outlook profile.

Also, in PSTs, you have this top-most folder which contains your other PST subfolders and other items like Deleted Items.  See the screen below:

During the import process, keep in mind that no email will be imported if they belong to that top-level folder, which in this case is April 2010. On the other hand, any and all subfolders under that will be imported (which means that the April 2010 Contents and Deleted Items folders’ contents will be included in the import). Just so everything will be clear.

Now, on to the import process. In Thunderbird 3.1, point to Tools > Import…

Then, a dialog box opens. Select the type of material to import, and choose Mail.

On the type of file that you would like to import, choose of course, Outlook. Not Outlook Express, if you really want to import your email.

Upon clicking Next, importing will begin. Several factors can affect the length of time before this finishes. It can include

  1. Size of the PST;
  2. Number of PSTs to be imported;
  3. Any other folders (i.e., Public Folders) that might also be in the Outlook profile

Eventually though, import will complete and will show a summary of successfully imported messages, as seen below:

Click on Finish. Make sure that all you need is found in Thunderbird’s Local Folders (or whatever you named it). If, for some reason, the import fails or some emails are missing, you can retry the procedure.

One downside to importing Outlook PSTs to Thunderbird, however, is that all decent formatting is stripped off when you view the messages in Thunderbird. All emails are considered plain text-formatted. It’s a small price to pay against the benefits of using Thunderbird and Zimbra. Also, Outlook contacts’ display names will only appear with their surnames, excluding first names or middle names. Again, a small price to pay for backward-compatibility. Anyway, what you should be more concerned about is the succeeding emails, right?

Lastly, a quick note on file size limits. Outlook PSTs have, for the longest time, been notorious for their 2GB file size limit. Well, your Thunderbird has just doubled that. Based on Mozilla’s wiki entry concerning limits on file size of email folders, the limit for each folder is 4GB. And the 4GB-per-folder rule excludes the size of any folders nested within that folder, and so on. And there is no specified limit on the number of folders you can create in Thunderbird. So, assuming you’re a relatively organized email user, having these shouldn’t pose a problem.

So there you have it. Happy importing and may you find the joys of using a new email.