I primarily use ubuntu linux on my home computer but I do have some Windows software that I still want to use (Medieval 2 Total War springs to mind). In Ubuntu it is easy to set up a computer in a dual-boot configuration, so whenever one turns it on, one can choose to boot either Linux or Windows.

One of the frustrations of the dual-boot configuration is that I often find myself in Windows, but all my saved e-mail is on the Linux part of the disk (which WIndows can’t see). There is a fairly easy way to fix this problem, though. This post explains how to share e-mail between Windows and Unix.

Step 1: Choose an E-mail Program

The first step is to choose and install e-mail software that’s available for both Linux and Windows. There’s a very common program that fits that requirement: Mozilla Thunderbird.

Step 2: Set up a Shared Disk

The next part is a little more technical. You need a place on the hard disk to store your e-mail that will be visible in both operating systems.

Windows and Linux use different disk formats for the hard disk. (Linux calls the format of a hard disk its “file system.”) Linux can see and read Windows-formatted disks, but the reverse is generally not true. Therefore, you should choose a Windows disk partition.

Depending on how you partitioned your hard disk when you installed Linux, Linux may already be installed on a Windows file system. Otherwise you’ll have to find a WIndows partition and mount it.

  1. To see all the disk partitions on your computer (on Linux), use the command fdisk -l (that’s an “ell”, not a “one). You’re looking for a partition marked “NTFS” or “VFAT.” Choose one of those as the shared area in which to store your e-mail
  2. Important: back up the configuration file /etc/fstab. You will need root privileges to do that; for example, sudo cp /etc/fstab /etc/fstab.original
  3. Create a directory where your Windows partition will be mounted, such as /media/shared_data. Again, you probably need to do this as root.
  4. Add a line to /etc/fstab to automatically mount the disk partition to the directory you just created. See the man pages for mount and fstab. You will want to set the options: rw, auto, uid=(your username), gid=(your group name).
  5. Manually mount the disk, as root: for example, sudo mount /media/shared_data
  6. If the mount command completed without errors, then you’ve successfully mounted the WIndows partition. Try creating a file (one way to do that is with touch) to test out the permissions.

That was the hard part. If you made it through that, you now have a disk partition that is shared between Linux and Windows, which you can use to store anything (not just e-mail).

Step 3: Configure Thunderbird

On the shared partition, create a directory where you want to save your e-mail. For example, create /media/shared_data/(your_username)/mail.

Right-click on the account name to see this menu

Right-click on the account name to see this menu

Open Thunderbird. If you do not have any e-mail accounts set up yet, create one now (File -> New -> Account). Do not check the “Use Global Inbox” check box.

For each account you want to share, right-click on the account name and click “Properties.”

The Account Settings window will come up.

Click “Server Settings.” Down at the bottom of the that window is a text box labeled “Local directory.” In that box, type the location where you want to keep your mail. If you have more than one account, it is a good idea to store each account in a different directory and to write down the location you’ve chosen for each account.

Thunderbird Account Settings dialog

Set the location for saved e-mail in Server Settings->Local directory

Now, reboot to WIndows and configure your accounts in Thunderbird to use the same local directory.

That’s all there is to it.