Convert Microsoft Outlook PST email to IMAP without Outlook

A client was going to stop using Microsoft Outlook and Exchange server and move their email to an ordinary web hosting company using IMAP. The client was downscaling and had no use of the benefits of Microsoft Exchange like shared contacts and calendars. They where just using it for email which could be obtained much cheaper by using the IMAP account at their web hosting provider.

So I was faced with the task of converting their old email contained in PST files. They had already shut down their Exchange server and I could not use the Outlook program. I just had the PST files that where exported before the server shutdown and needed them imported into the IMAP account without using Outlook as it was not availible for me.

This is how I solved it.

Tools used:

• Thunderbird for Windows downloaded here
• ImportExportTools for Thunderbird downloaded here
• SysTools PST converter downloaded/purchased here

1. Download and install Thunderbird. Set it up with the target email account both as an IMAP account and a POP3 account (it was a problem importing the converted eml files directly to the IMAP account so I had to import them to the POP3 account which is stored locally and then drag them over to the IMAP account, more about that later on). Make sure you setup the POP3 account to leave mail on server and not delete mail when deleted locally.
2. Download the ImportExportTools extension for Thunderbird. Drag the downloaded file onto Thunderbird in the task bar to install it.
3. Download the free trial of the SysTools PST converter and install it. The free version is limited to 25 emails per folder so if you have more emails you need to purchase it ($49 when writing this article). You can make a test run with the free version so you see everything works before you go on and buy it.
4. Run the SysTools PST converter.
5. Click the Add file button and select your PST file.
6. Click the Export button and select EML format, and check the folders you wish to export (normally the top folder). Enter a target folder. Then click the Export button.
7. In Thunderbird, right click the POP3 email account and select New folder and call it “From PST” for example.
8. Select the “From PST” folder and go to the menu icon in Thunderbird and select Tools -> ImportExport-tools -> Import all EML from a folder -> and it’s subfolders. Select the top folder of your email export in step 6 and click Select folder.
9. All subfolder and it’s email should now turn up in the “From PST” folder. Now drag the “From PST” folder from the POP3 account to the IMAP account in Thunderbird.
10. Finally delete the POP3 account in Thunderbird.