This reference will help you have the best possible experience using Thunderbird Daily (which we will refer to as Daily), where new features are developed and testing begins. This is the least stable channel of Thunderbird code. Make sure you back up important data regularly.

You can help by testing, and reporting bugs before they reach release. Thank you for your interest in using Daily!

README BEFORE using Daily

• Protect your Thunderbird data by doing regular backups of your Thunderbird profile.
• High-impact flaws such as data loss may occur. Protect yourself with backups.
• New features require new code, so flaws are possible. Flaws may not be fixed quickly because of competing priorities, but do report them. Do remember that patience is required when using test versions.
• Subscribe and contribute to the Thunderbird Daily topicbox community mailing list to share your thoughts, learn about new features and user experience.
• Thunderbird Daily is updated daily.
• Make sure your installer does not install Daily in a non-Daily program directory - official Mozilla downloads should do this correctly. See How to install and run Daily for more information.
• If you use Thunderbird mail filters and you have more than one Thunderbird data profile, decide where you want to run your filters - in your Daily profile or your other profile. Do not use filters in both.
• Add-on authors are not obligated to make their add-ons work in Daily, so many of your add-ons may not work. Please submit your issues to the add-on author, and consult the Add-ons FAQ if you have difficulties.
• Are you using POP accounts? Unlike IMAP accounts, your only copy of POP mail is in your local Thunderbird data profile and not on a server (unless you changed the default settings). To use a POP account with Daily you must choose between these options:
  • Don't use a POP account with your Daily install: Using POP is not recommended, because you risk losing your email if you do not configure ALL of your email clients correctly with your POP accounts.
  • If you have to use POP:
    1. Set all of your email clients, including Thunderbird for Android and Thunderbird Desktop, Outlook, etc., to Leave messages on server in ≡ > Account Settings > Server Settings (or equivalent in your email clients).
    2. Uncheck For at most [X] days.
    3. Manually delete messages from the POP server. We recommend you do not use Fetch headers only or equivalent in your non Thunderbird email clients.

Resources, assistance and references

How you can help improve Thunderbird, find help, and give help:

• Review the README above.
• Post questions about normal Thunderbird usage in Thunderbird support aka SUMO.
• Answer questions about Thunderbird usage in SUMO.
• Ask and help with Daily-specific questions in the Thunderbird Daily topicbox community mailing list.
• Report bugs that you find. Report performance issues by creating a performance profile and adding it to your bug report or support posting.
• Daily does not have Release Notes. But you can get a sense, after the fact, by looking at Beta release notes. You can also follow comm-central checkings via the web page or subscribe to the comm-central RSS feed.
• Please submit all crash reports.
• Backup your profile with ≡ > Tools > Export.
• Review the Daily Start Page which has handy information, accessed in Thunderbird with Alt > Go > Mail Start Page (keyboard shortcuts), or in your browser.
• Join us in other ways to contribute to the project.

Add-ons

Add-on authors are not obligated to have their add-ons work in Daily. Some might not work. Consult the add-ons FAQ if you have difficulty.

How to install and run Daily

Install Thunderbird Daily into its own program directory. If you download Daily from official sources, then installation should happen correctly. Do check that it installs to its own program directory, for example C:\Program Files\Mozilla Thunderbird Daily. If you need more help, please refer to installation instructions for Windows, macOS, Linux, and official sources for additional details.

Quick links to official Daily sources:

• Windows, macOS and Linux via Thunderbird download page - choose the Daily channel.

How do I change from a Daily version back to a beta version?

• Please do not change from Daily to beta by installing beta into the Daily program folder.
• Please do not point a beta install to a Daily data profile.

Why? Because accessing data with an older version number of the program risks instability and corrupt data.

Instead, make a separate profile for beta, and transfer any data you need from the Daily profile using standard tools, for example Address Book (AltCtrl + 2) > Export/Import, or ≡ > Tools > Export. Exceptions:

• For POP and local mail: In the Mail directory of your Thunderbird profile you will find both the Local Folders directory and POP account directories. You can copy the contents of these from one profile to another, but take care to NOT overwrite any msgFilters.dat files, as they contain your filter rules.
  WARNING: Files from a newer version are not guaranteed to work in an older version.
• For IMAP accounts, there should be no need to copy any IMAP data files from a Daily profile to your other profile.

Daily isn't for me. How can I help?

Participate lists many ways for you to help in the community, and places to learn more about Thunderbird.