From MozillaZine Knowledge Base

This article was written for Thunderbird but also applies to Mozilla Suite / SeaMonkey (though some menu sequences may differ).

This article gives step by step instructions for how to import folders from another profile for a new user who has never installed an extension. It assumes you're using Windows but you should still be able to follow the instructions using a file manager on another operating system.

Install the ImportExportTool extension

Note: This extension was originally called the mboximport extenson

• Go to this web site using your browser. If that web site is temporarily unavailable you could use this older version
• Right click on the download link and choose "save link as" (or "save target as") from the context menu to download the file. You want to right click to avoid Firefox thinking that you're trying to install that extension in it.
• Start Thunderbird.
• Go to Tools -> Extensions and press the Install button.
• Browse to where you downloaded the .xpi file, select it and press Open.
• It will then display a "Software Installation" screen with a grayed out "Install" button. After a couple of seconds it will finish processing the .xpi file and replace that button with a "Install Now" button. Press the button.
• Exit Thunderbird.
• Start Thunderbird again. It should now have a Tools -> Import/Export in mbox/eml format command.

Find your old profile

Your folders are stored as mbox files in a profile. These are text files with the folders name and no file extension. For example your inbox folder is the "inbox." file. You can safely read one using a text editor to verify it contains mail messages though its not user friendly because it contains the raw message source, including all of the headers and big blocks of characters all run together whenever you have a binary attachment.

• Read this article to figure out where your profile is stored.

• Go to your profile directory using Windows Explorer. If you're not sure you found a profile look for a prefs.js file and a Mail subdirectory.

If you're running Windows 2000 or later you may need to enable "Show hidden files and folders" and disable "Hide extensions for known file types" (its under the Hidden files and folders heading) and "Hide protected operating system files (Recommended)" in Tools -> Folder Options -> View to see it. You may get a warning message that your computer won't work if you do this. Changing those settings causes no harm, its really warning you not to change or delete any of the files or directories used to store the operating system. See this thread if you're running a older version of Windows.

Find the folders

If the folder was in Local Folders or you used a global inbox it will be somewhere in the Mail\Local Folders directory. Otherwise look for a subdirectory named after the accounts mail server. For example, if you're using gmail your inbox would be the "inbox." file at Mail\pop.gmail.com.

Ignore the .msf files, they don't have any messages. You want the files with the folders name and no file extension.

Thunderbird uses *.sbd subdirectories to create a folder hierarchy. So a Local Folders\1\2\xyz child folder would be the "xyz." file at Mail\Local Folders\1.sbd\2.sbd\3.sbd . That directory would also have a empty xyz.sbd subdirectory created in preperation for you someday creating a child folder of xyz. Ignore it.

Import the folders

• Select either the Local Folders directory or the POP account you want to import the folder into, in Thunderbird.
• Tools -> Import/Export in mbox/eml format -> import mbox file
• Browse to the mbox file and press the Open button.
• Thunderbird will import that folder. It may add a suffix to make the folder name unique. For example, when I imported "inbox." into Local Folders it created a inbox679 folder.
• Repeat as needed. Note that you can import multiple folders in one step by holding down the Control key while clicking on them in Tools -> Import/Export -> import mbox file.

See also

• Create/delete profiles or change the default profile using the profile manager.
• How to keep Thunderbird working smoothly.
• Moving address books between profiles
• Moving your profile. Note that you can restore a backed up profile by moving it if you have the entire profile.
• Recovering a profile that suddenly disappeared.
• Storing your messages outside of the profile.