.eml to mbox

Microsoft uses the .eml format to store email messages locally. Open source alternatives to Outlook, Outlook Express or Windows Mail typically use the .mbox format. If you have used IMAP Size or Outlook to archive your email, then you will need to follow this tutorial in order to move your archive onto a linux-based operating system.

This process will also work if you want to view your archived mail on a Windows PC using Mozilla Thunderbird as the email client.

Archive using IMAP Size

This step will have to be peformed in a windows environment.

First, archive your mail using IMAP size. If you have not yet installed and configured the software, please follow the directions available .

1. Choose the folders you want to archive. 

2. Click "Tools" -> "eml2mboxes" and locate the directory where you backed up your mail.
Define a directory where converted mbox files will be placed. 

3. You should now have an .mbox file for each folder you archived and one for the root. Put these files onto a removable storage device, such as a USB Disk. 

4. Switch to your linux-based operating system and launch Thunderbird, or open Thunderbird on your Windows PC.

5. If you have never run the software before, you will be prompted to create a new account. If an account already exists, skip to step 9.

6. Choose a "Unix Mailspool" and continue. (The goal here is to create a dummy account we can delete later, so don't worry too much about the particulars.) 

7. When prompted to configure an outgoing server, type in whatever you like. In this case, I chose "completely.bogus.server". Finish creating the dummy account. 

8. Next, click "Edit" -> "Account Settings" and remove the account which you just created. The "Local Folders" section will stay. 

9. Click on "Local Folders" on the left.

10. You can change the "Account Name" from "Local Folders" to "Ucalgary Backup" or "My Awesome Undergrad". Copy the path from the "Local Directory" text box. Click on the box, hold ctrl+a to select all and then copy the path. 

11. Open this path in Finder, Windows Explorer or Nautilus and open the folder of .mbox files on your removable storage device. You will get something that looks like this: 

12. Next, copy the .mbox files from the removable storage device to the "Local Directory" folder. 

13. Close Thunderbird and re-open the program. Your archived mail is now available in Thunderbird.