Migrating Mozilla Thunderbird From One Computer To Another

Thunderbird 3Mozilla Thunderbird may be an excellent email client (and PIM with the right extensions) but for all the wealth of extensions available and it’s myriad of import options, it’s still incredibly difficult to export data such as email, accounts and settings.

I faced that very problem today.

When I’m developing or doing video editing on my main laptop I don’t want to have my email client running. Having it open is not only a distraction but sucks up valuable resources, so today I decided to install a second copy of Thunderbird on my other machine so I could access my email no matter what I was doing or running.

I access all of my email through IMAP, so if I had just a single email address I wouldn’t have worried too much about just installing Thunderbird and manually setting up the account. Unfortunately I am not blessed enough to get by with just a single email address, not even remotely close, so other methods were required.

The method I’m about to show you will work on Windows XP, Vista, Windows 7 & Windows 8, can be accomplished in less than 10 minutes and will allow you keep all of your email settings and email (doesn’t matter if you use POP3 or IMAP).

In order to make the migration, you’ll need a flash drive (preferably with a large storage capacity if you are a POP3 user), portable hard drive or a network connection with shared folders between both machines.

I’ll be explaining how to do it using a flash drive or portable hard drive.

Okay lets get started shall we?

Download the latest version of Thunderbird to the machine you want to install it on ans start the installation process.

While that is installing got to the machine where your email currently exists.

Make sure that Thunderbird isn’t running and plug in your thumbdrive.

Windows Vista and Windows 7 navigate to the following location:


Windows XP users browse to:

C:\Documents and Settings\Paul\Application Data\Thunderbird\Profiles

Inside that folder you’ll see a file that should be named something like: XXXXXXX.default

Copy this file to your flash drive. You may need to compress it using a tool like 7Zip if it’s too large to fit on the flash drive.

Once it’s copied eject the thumbdrive and and take it back to the machine you just installed Thunderbird on.

Make sure Thunderbird is fully installed and then run Thunderbird for the first time.

Once it starts exit out immediately. Don’t enter any data or set anything up. By letting it run once it sets up all the folders you need in your Application Data folder which we can now replace with the file on your flash drive.

Once Thunderbird is closed, navigate to the same folder as you were at before (except on the new machine) and delete the XXXXXXX.default file you find in there.

Once it’s deleted copy the XXXXXXX.default file from your thumbdrive (decompress if necessary) into the folder.

Next Windows Vista and Windows 7 users should navigate to:

Windows Vista and Windows 7 navigate to the following location:


Windows XP users navigate to:

C:\Documents and Settings\Paul\Application Data\Thunderbird

Inside this folder you’ll find a file called profiles.ini.

Open profiles.ini using Notepad or your favorite text editor.

It should look something like this:







Change the value of XXXXXXX.default in profiles.ini to match the value of the original XXXXXXX.default file you copied from your flash drive.

Save the file, close all open windows and start Thunderbird.

If you’ve done everything correctly Thunderbird should start up without problems.

If you get an error saying something like: “Thunderbird is already running in another window“, then recheck the value of XXXXXXX.default in profiles.ini.

If it doesn’t match the original value then things won’t work and Thunderbird will keep throwing that error.

If  you originally created your signatures for your email accounts inside Thunderbird then you’re all done.

If, like me, you’ve got them saved as text files then you’ll need to copy them to the new machine and go into the account settings for each email account and make sure that it is pointing to the correct location for you signature files.

That’s it, you’re all done :)