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Thunderbird FAQ

This is the Thunderbird FAQ, which contains the most frequently asked questions about the mail client.


General Questions

What is Thunderbird?

Thunderbird is a free, open-source and cross-platform mail client for most operating systems including, but not limited to, Windows, Linux and Macintosh. It is based on the Mozilla codebase. It is a robust and easy to use client, similar to competing products like Outlook Express, but with some major advantages such as junk mail classification. Read more about the mail client at the Product Page.

Why should I use Thunderbird instead of other mail clients?

There are too many reasons to list them all here. Read why you should use Thunderbird instead of other mail clients on the market.

Is Thunderbird free?

Yes! Thunderbird is open source software, meaning that anyone has the right download and use the program for free, and view and modify the source code under the terms of the license.

Where can I download Thunderbird?

To download Thunderbird, go to

How do I install Thunderbird?

See the release notes for more information.

How do I uninstall Thunderbird?

See the release notes for more information.

Is Thunderbird available in my language?

Possibly. Since Mozilla Thunderbird is an open-source project, contributors are constantly translating Mozilla Thunderbird into other languages. You can check if Mozilla Thunderbird is available in your language in the localized builds list.

Where are my mail, passwords and other personal information saved?

Thunderbird stores your personal settings in a profile folder. See the next frequently asked question for more information on how to manage the profiles.

How do I start the Profile Manager?

The Profile Manager is used to manage multiple profiles. To start the Profile Manager, follow the steps in the Manage Profiles How-To.

How do I move my profile or restore a backed up copy?

It's possible to move the location of a profile folder. This could be useful if you have a backed up profile folder somewhere on your hard drive and want to tell Thunderbird to use that as your profile. Read about moving an existing profile or restore a backed up profile for detailed instructions.


How do I migrate my Mozilla mail and settings to Thunderbird?

Thunderbird includes an auto migration tool that imports your Mozilla 1.x or Netscape 7.x profile directly into Thunderbird without you having to do anything.

Can I access my Yahoo!, Hotmail, Lycos (Europe), MailDotCom, Gmail, and Libero WebMail account through Thunderbird?

Yes. The Webmail extension integrates web site based email accounts into Thunderbird, allowing Thunderbird to download and to send emails using the web site. Some services may require a subscription for this type of access. Current information on the Webmail extension, supported services, and other add-ons for web based email can be found at the WebMail development site.

Can I access AOL and Netscape e-mail using Thunderbird?

Yes. AOL and migrated Netscape users can read their AOL/AIM mail using Thunderbird. In order to do this, setup a new mail account (File > New > Account...) and select IMAP as the incoming server type and enter or as the address. Enter your screen name as the user name.

You must also setup the outgoing (SMTP) server in order to send e-mail. To do this, select Tools > Account Settings... and then select the "Outgoing Server (SMTP)" item in the list and click Add.... Enter as the Server Name, use port 587 and enter your AOL screen name as the User Name (you will be asked for the password later). Click OK and go back to the Account Settings window. Now locate and select your newly created mail account and near the bottom, select the Outgoing Server (SMTP) that you created.

Note that you cannot manually add messages to the Inbox or Sent Items folders. Messages will only be added to these folders when an e-mail is received or sent by the AOL IMAP server. Therefore, make sure you use local folders for Sent, Drafts and Templates. To specify this, open the Account Settings again and select the "Copies & Folders" item under the AOL account.

More information on using third-party email clients may be found on AOL's Help pages, select E-Mail > Third Party E-Mail Applications.

How do I import e-mail messages from kmail (Linux)?

Make a new folder in kmail and name it inboxmbox. You'll see a dialogue in which you can save it as an mbox folder. Copy all posts in your kmail inbox folder to the new inboxmbox folder. Exit kmail. Next, copy or move inboxmbox to the subfolder Mail/Local Folders in your profile folder. When you open Thunderbird you'll see the inboxmbox folder under Local Folders. Copy the messages into your Inbox folder if you like.

How do I import e-mail messages from (MacOS X)?

Go to ~/Library/Mail/ and root out the .mbox files in the finder. These are actually OSX packages. Select Show Package Contents and a new window will open revealing several files including a file named mbox. Copy that file to the subfolder called Local Folders in the folder Mail in your profile folder and rename it to something meaningful. This process needs to be done for each of your mailboxes. Finally start Thunderbird to see the new mail folders.

Mail 2.0 does not store message folders in mbox format; so you'll need to export your folders to mbox format. In, use Edit > Select All to select all messages in a folder, then use File > Save As to save the messages in "Raw Message Source" format. The resulting file will be an mbox file, that you can copy to your Thunderbird profile.

How do I import the address book (MacOS X)?

You can use the Address Book Exporter application to export your address book to a plain text file. Then, in Thunderbird, select Tools > Import..., select Address Books, click Next and to import a text file.

How do I import e-mail messages from another mail program?

Go to Tools > Import, which will bring up a dialog to guide you through the process.

How do I export e-mail messages to another mail program or computer?

Thunderbird's mail files are in the standard plain text "mbox" format, which almost all mail programs can use or import. Many proprietary mail programs have a function to import from Eudora, which also uses the "mbox" format; this function should read your Mozilla mail files properly.

Your mail files are inside your profile (see the Profile Folder), in the Mail and (if you use IMAP) ImapMail folders. Each mail folder (Inbox, Sent, etc.) is stored as two files — one with no extension (e.g. INBOX), which is the mail file itself (in "mbox" format), and one with an .msf extension (e.g. INBOX.msf), which is the index (Mail Summary File) to the mail file. Tell the other program to import mail from the file with no extension.

If you want to transfer a mail file to another Mozilla profile or another installation of Mozilla, simply put the mail file into the other installation's Mail folder.


How do I customize the toolbar?

You can customize the toolbars by choosing which buttons you want to show, by adding toolbars, or by resizing the buttons. To do so, go to View > Toolbars > Customize.... A new window will pop up, containing available toolbar items. Just drag and drop them to the toolbar where you want to add them. To remove some items from the toolbar, drag them from the toolbars and drop them at the Customize window.

You can even place toolbar items on the menu bar! This will allow you to place everything on one row, saving lots of screen real estate.

How do I make Thunderbird my default mail program?

The first time you run Thunderbird, it should ask you if you want to make it your default mail client. If you answered no and later decide you would like it to act as your default mail client:

  • Windows, Mac: go to Tools > Options... (Thunderbird > Preferences... on Mac), select the General section, then click on Check Now, and check E-Mail, then click OK. If you still have problems with mailto: links under Windows, go to Start > Control Panel and open Internet Options. Under the Programs tab, select Mozilla Thunderbird from the drop-down list next to E-mail:.
  • Gnome (Unix/Linux): In the Gnome main menu, go to System > Preferences > Preferred Applications and then under the Mail Reader option, select Mozilla Thunderbird.
  • KDE 3.x (Unix/Linux): Open the Control Center and go to Network > Email. Under Preferred Email Client, enter: absolute path of Thunderbird install directory/mozilla --mail
How do I use the spam filters?

Mozilla Thunderbird comes with build-in spam filters, effectively moving (or removing) unwanted e-mail messages from your mail folders. There is a great article at Mozilla Developer Center explaining how to fight junk mail with Netscape 7.1. This article applies to Mozilla Thunderbird too.

Does Thunderbird come with a spell checker?


What's the keyboard shortcut for [random feature]?

See the Keyboard Shortcuts table on this site for a list of the most common keyboard shortcuts.

Can I use different themes for Thunderbird?

Yes! Please visit the Themes section for a list of the available themes.

Is Thunderbird susceptible to e-mail viruses?

Thunderbird will not allow a virus or worm to execute automatically. You can see what attachments have been sent to you without a virus being able to execute, and you would have to save a file to your system and deliberately run it before it could cause any harm.

JavaScript is switched off by default for mail and news, so an e-mail cannot run script code just by being opened.

As with any mail program, take proper caution before running any file that you receive in e-mail. Appropriate anti-virus software should also help keep you safer.

Is there a mail notifier in Thunderbird?

Yes, the Windows version of Thunderbird includes mail notification in the system tray while Thunderbird is open.

How do I set Thunderbird to go directly to my Inbox?

Instead of displaying the Mail Start Page, Thunderbird can take you straight to your Inbox when starting up, saving you one mouse click. To do this, simply set your default account to check for new messages at start up. Go to Tools > Account Settings... (Edit > Account Settings... on Linux), select your default mail account, click "Server Settings", and check the Check for new messages at startup option.

How do I use S/MIME, PGP or GnuPG to send and receive signed or encrypted messages?

To use S/MIME, go to Tools > Account Settings... > account name > Security (Edit > Account Settings... on Linux). You can set which certificates to use with each account for digital signing and/or encryption.

Hooks to PGP or GnuPG are not included in Thunderbird, but are under development at Enigmail.

I changed my IMAP password, how do I get rid of a cached password?

In the menu, select Tools > Options... (Edit > Preferences... under Linux), click on Privacy, choose the Passwords tab and click Edit Saved Passwords. Select the site/username line you want to delete and click Remove. When done, click Close and restart Mozilla Thunderbird.

How can I access/change the Master Password?

Go to Tools > Options... (Edit > Preferences... under Linux), select the Privacy section, click the Passwords tab and finally click the Set Master Password... button.

© 2002-2006 David Tenser.