Mozilla Thunderbird, Portable Edition Support

Many of the most common issues that arise when using Thunderbird Portable are addressed here. Please read through the various topics to see if any of them address your question. You can also post a note to the Thunderbird Portable Support Forum.

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Thunderbird Portable-Specific Issues

General Mozilla Thunderbird Issues

Adding GPG and Enigmail

Mozilla Thunderbird, Portable Edition no longer supports Enigmail as it has built in support for GPG. You can read more in the OpenPGP in Thunderbird - HOWTO and FAQ topic.

Adding the Address Book to the Menu

A direct link to the address book within Mozilla Thunderbird, Portable Edition is useful when you just want to look up an address or quickly access other information in the address book. You can easily add an icon for the address book to your Menu by downloading Mozilla Thunderbird, Address Book (<1MB download / <1MB installed) and installing it. It will automatically create a new address book icon for you.

Copying Your Local Thunderbird Settings

If you're using a local copy of Thunderbird, you may wish to just copy your local Thunderbird settings right into Thunderbird Portable. Your local Thunderbird profile is usually installed in C:\Documents and Settings\[user]\Application Data\Thunderbird\Profiles\default.???\ or C:\Users\[user]\AppData\Thunderbird\profiles\default.???. Just copy all of those files to the Data\profile directory within Thunderbird Portable. Sometimes, certain profiles will cause the launcher to fail or hang. In that case, start from scratch and try just copying your mailstores (Mail and ImapMail directories) as well as your prefs.js and abook.mab files.

Using a Second (or Third) Profile with Thunderbird Portable

A second profile can allows you to setup another set of settings (email, rss feeds, preferences, etc) for Thunderbird Portable that you can use independent of your main settings. This is useful for sharing a flash drive with someone, testing extensions and configuration options or separating our work from personal details.

To use a second profile, install the Thunderbird Portable 2nd Profile 2.0.1 app in the same PortableApps directory that ThunderbirdPortable is in (so, if Thunderbird Portable is installed to X:\PortableApps\ThunderbirdPortable, you'd install this to X:\PortableApps\ThunderbirdPortable2ndProfile). In the Menu, it will show up as "Mozilla Thunderbird, Portable Edition 2nd Profile". You can easily rename it to something more useful by right-clicking and selecting rename. When you run it, it will start Thunderbird Portable up with your second profile without affecting your main profile. You can even install a 3rd or 4th profile by installing the 2nd Profile app again to another location (like X:\PortableApps\ThunderbirdPortable2ndProfile_Copy_1 so the platform will automatically update it) and then renaming it in the Menu.

Improving Thunderbird Portable's Performance

Thunderbird Portable 3's performance may be improved on slower flash drives by disabling certain features. Unlike Thunderbird 2, version 3 syncs all your IMAP folders by default and does a full-text index of all messages in all accounts to make searches from the search bar possible. Both features result in additional data being written to the drive on a regular basis which can impact performance.

To disable the global search indexer, open the options window (click Tools then Options). Click Advanced, then General, then Advanced Configuration. Uncheck the Enable Global Search and Indexer. Click OK.

To disable message sync, open the accounts settings window (click Tools and then Account Settings). For each IMAP account, choose the Synchronization & Storage option and under Message Synchronization uncheck Keep Messages For This Account On This Computer. Click OK when done.

Running From a CD (Thunderbird Portable Live)

Thunderbird Portable supports running from a CD right out of the box, and it's a snap. Start off by downloading and installing Thunderbird Portable to your hard drive... it doesn't matter where. Run it at least once to generate the default settings. Then, customize it as needed, being sure not to move ThunderbirdPortable.exe or any of the other critical files. Next, download ThunderbirdPortable.ini and save it to the same directory as ThunderbirdPortable.exe. Then, burn the whole ThunderbirdPortable directory to a CD and you're ready to go. Note that Thunderbird doesn't actually support running directly from read-only media, so the portable app and the profile are copied to the local PC's temp directory and run from there.

If you use Thunderbird Portable from a USB flash drive with a write-protect switch, you're covered, too. The Thunderbird Portable Launcher will automatically detect when you protect the drive and offer to run your files locally for you.

Additional information about the options in the INI is provided in the readme.txt file within the ThunderbirdPortable\Other\ThunderbirdPortableSource directory. Please note that you must follow Mozilla's Trademark Distribution Guidelines if you are distributing your customized version to anyone else.

Live Mode Patch: There is a bug in the current launcher that prevents live mode from working properly. A patch is available here and will be included in the next release.

Using Thunderbird with Webmail (Hotmail, Yahoo, etc)

You can use Thunderbird and Thunderbird Portable with many popular webmail providers by using the Webmail Extension. It allows you to connect to Hotmail, Yahoo, Lycos,, Gmail, Libero and AOL. Details on installing and configuring as well as a support forum are all linked to from their homepage. Just be sure to remember that, like most mail clients, Thunderbird is configured to download and remove your mail from the server by default. If you don't want that to happen, update your account settings after setting up your account (and before checking your email).

Known Issues

The following are known issues with this package:

  • Trojan/Virus detected - AntiVir and Avast, on more than one occasion, have claimed there is a trojan or virus in the launcher. This is due to issues with trojan detection that will occasionally mis-identify many NSIS-based applications as trojans. It will usually occur after a definitions update. You should contact your antivitus provider and let them know of their mistake.
  • Themes and Extensions - Most themes and extensions should now work with Thunderbird Portable -- including those that make use of the component registry. A handful will still fail, though.


I made some modifications to the official version of Thunderbird to make it more USB key friendly (decreasing total install size and the number of writes to the drive, which will increase drive life). These changes are listed here so you'll know what they are, and so you can recreate the process, if so desired.

  • Extension-Friendly Launcher - PortableThunderbird Launcher is included by default. It will alter the paths to any extensions you install to work relatively. Just be sure to close/restart Thunderbird before switching PCs.
  • Default Profile - A default profile exists within the thunderbird directory.
  • No Email Address Saving - Thunderbird won't automatically save addresses to the address book.
  • No Default Mail Client Check - Thunderbird won't check if it is the default mail client and the registry key it updates will be reset on exit.

Additional Recommended Settings

  • Compact Folders - You may wish to set Thunderbird to notify you when compacting your mail folders would save you space. (When you delete an email in Thunderbird, it still takes up space in the folder on the disc until you compact that folder.) You can find this setting within Tools - Options - Advanced - Offline & Disc Space. Check off the box and enter a value. I recommend 2mb for most people when running portably. You can also right-click a folder and select Compact This Folder anytime you'd like.
  • Fetch Headers Only (POP Accounts) - Thunderbird can be set to only download headers from the mail server. This option can be turned on within Account Settings under Server Settings. Though this will make messages take longer to come up, it may decrease the number of writes to the USB drive, increasing drive life.

Version History

  • - March 5, 2007
    • Thunderbird updated to
    • Slight name change to Mozilla Thunderbird, Portable Edition