The chair of the Mozilla Foundation stated that Mozilla will stop developing Thunderbird in a July 2012 post that has been widely mis-interpreted as meaning Thunderbird is dead. Part of the bad PR was caused by people not being aware that the community had already been doing a significant amount of the development, and that the community did not agree with his conclusion that "it is already pretty much what its users want and mostly needs some on-going maintenance". Many people are also unaware that another project survived after Mozilla stopped development. SeaMonkey was formed 8 years ago after Mozilla stopped releasing new versions of the former Mozilla Application Suite. It is now a thriving community-driven product.
The Thunderbird project is not dead. It is still a Mozilla project even though new development and bug fixing is now done by the community. Mozilla continues to provide the infrastructure (both the Mozilla add-ons web site and the servers used to build, test and distribute new versions), and add stability/security fixes. The main effect was that the pace of development slowed and there was a temporary loss of leadership. However, the project has successfully moved from a staff led to a community led project. At a October 2014 summit meeting of 22 active contributors they decided that for the next major release (Thunderbird 38 due in June 2015) that they will:
- Add support for mbox based mail folders larger than 4GB. (Backend work done)
- Finish support for using maildir files as an alternative to mbox files. Maildir files are similar to *.eml files, but have a UNIX heritage.
- Add support for WebRTC to instant messaging. (Was dropped from the roadmap)
- Merge the Lightning calendar add-on as a shipped (but disabled by default) add-on. (Done)
- Merge the New Account Types binary addon into core, allowing new account types to be defined using addons in the future. (Done)
- Support OAUTH authorization in GMail IMAP accounts. (Done)
According to Thunderbird Usage Continues to Grow there are approximately 27 million active monthly users. There are no statistics available on what percentage of Thunderbird users are on each operating system, but if you assume it matches the statistics for the Lightning add-on, 85% are using Windows, 12% Linux, and 3% OS X. Readopting Thunderbird is a interesting blog post about how Thunderbird needs Mozilla, but also vice-versa.
Firefox and Thunderbird: A Fork in the Road describes the Mozilla Foundation's view of several recent steps towards the independence of Thunderbird. Simon Phipp's report "Finding a Home for Thunderbird" summarizes the pros and cons for the four choices being considered. One of the potential sources of funding is the p≡p Foundation which would like Thunderbird to include easy-to-use encryption.
How to ask for help.
Please don't send a private message to a moderator to ask for technical help. Either create a new thread and ask a question, use the search field (to the right) to search for threads about similar topics, or look in the knowledge base (to the right). If you find a old thread about a similar problem and want to ask for help, please create a new thread instead if its over a year old.
If you create a thread please
- Mention the version number in Help -> About Mozilla Thunderbird, what operating system you're using, and the exact text of any error message.
- Use a descriptive title such as "contact sidebar vanished", don't just say you need help. If you're running OS X or Linux mention the operating system in the title to help other users with that background notice your thread.
- Don't post your email address.
- If you need to provide a picture see Post a screen shot on the forum
Some good articles for new users:
Getting started with Thunderbird.
Common misconceptions about Thunderbird
How to keep Thunderbird working (aka How not to shoot yourself in the foot)
SSL security errors
Moving your profile
Move to a new PC
Using Gmail with Thunderbird.
How do you backup Thunderbird?
Add-on doesn't support your version of Thunderbird
Many add-ons are automatically disabled by Thunderbird 5.0 or later because they have a maximum version field that indicates they only support up to Thunderbird 3.3. However, many add-ons will work if you bump the maximum version they support, despite tools -> add-ons complaining that is it incompatible. The easiest way to do that is to install the Disable Add-on Compatibility Checks add-on. That will automatically disable version checking so that you can try the add-on. Ignore the warning message that the add-on is not compatible. If you run into a problem just uninstall the add-on. If you can't do that, use "help -> restart with add-ons disabled" to disable all add-ons and then uninstall the one that doesn't work.
See Go back to an old version of Thunderbird if you want to go back to an earlier version . Uninstalling Thunderbird does not delete your profile, which has your mail, settings, address books, add-ons etc. If you're worried backup your profile first using one of the suggestions in Profile backup or Third party profile backup software and services
Formal support for Windows 10 was added in version 38.2.0
One of the problems when looking at threads about Thunderbird under Windows 10 is its sometimes not clear if its really a Thunderbird problem, a Windows 10 specific problem, or due to a problem with that machines Windows drivers. If you have problems under Windows 10 try:
- Checking that Thunderbird was added to the firewall rules (especially if it appears to freeze)
Disabling notifications in tools -> options -> general
Disabling hardware acceleration in tools -> options -> advanced -> general.
Running Thunderbird in safe mode (help -> restart with add-ons disabled)
Running Windows in safe mode with networking enabled
Modifying the shortcuts properties to run in Windows 7 compatibility mode, and default to run as administrator
All of the Windows 10 bug reports.
Unsupported Operating System
See Unsupported Operating Systems if Thunderbird no longer supports your Operating System. There are several workarounds available such as a third party build of Thunderbird called TenFourBird if you are using a PowerPC Mac running Tiger or Leopard.
Lightning (calendar) problems
Check if there is a release candidate at the Mozilla Calendar Project Blog. The Lightning add-on web page has a "development channel" at the bottom. Click on that if you're interested in finding out how to get experimental versions of Lightning. Its typically the only version that will work with beta versions of Thunderbird.
EarlyBird and Beta versions
Earlybird and beta versions of Thunderbird are available here.
A side effect of installing a beta is that it puts you on the beta channel, so that whenever you check for upgrades it will look for both new releases and betas. The channel information is stored in the programs directory, so if you uninstall you start fresh. Uninstalling doesn't delete your profile, which contains your mail, address books, settings, add-ons etc.
Tech Support Scam
Mozilla does not offer telephone support or paid technical support for Thunderbird, and does not recommend any companies that do that. However, there have been cases were somebody used a legitimate technical support company that did not make any false claims, but the user thought they were dealing with Mozilla because they incorrectly connected the dots . You can report a web site that you believe is using Mozilla's trademarks to mislead people into thinking the site is an official Mozilla site or sponsored by Mozilla to Mozilla's legal dept. at https://www.mozilla.org/en-US/about/legal/fraud-report/ .
Its against the rules for anybody in these forums to remotely access your PC. Its too prone to abuse, and we want to help people in a way that information is shared with other users. Most problems are not new.