Whether you are just curious or already using beta, this article will help you have the best possible experience. Using Beta is a great way for you to help the global Thunderbird community and improve the product, by testing fixes and new features, and discovering and reporting bugs before they reach release. Thank you for your interest in using beta!

README BEFORE using beta

Don't be intimidated by this common sense list - they are presented here for your protection.

• Protect your Thunderbird data by doing regular backups of your Thunderbird profile.
• High-impact flaws such as data loss are rare but may occur, so protect your data with backups.
• New features require new code, so flaws are possible. Please report flaws, but please be patient because flaws in test versions may not be fixed quickly because of competing development priorities.
• Use the beta topicbox to learn about new features and connect with the experience of other beta users.
• Expect frequent updates, which we use to quickly provide improvements and fixes.
• If you use filters then you must decide where to run your filters for which email accounts - in your beta profile or your other profile. Do not use filters for an account in both profiles.
• Some add-ons may not work in beta. If you have difficulty, please submit your issues to the add-on author, and consult the Add-ons FAQ.
• If you using POP accounts you must make a choice, because your only copy of POP mail is on your computer in one Thunderbird profile and not on a mail server (unless you changed the default settings):
  • Don't use a POP account with your beta or 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.
  • Change your account in Thunderbird to use IMAP instead of POP.
  • If you have to use POP:
    1. Set all of your email clients (Thunderbird for Android, 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.
    4. We recommend that you do not use Fetch headers only in Thunderbird, nor a similar setting in other Email clients.

Resources, assistance and references

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

• Ask and answer beta-specific questions in the beta topicbox community.
• Post general Thunderbird questions in Thunderbird support (SUMO). You can also answer SUMO questions.
• Report bugs that you find. Report performance issues by creating a performance profile and add it to your bug report.
• Read informative Release Notes at ≡ > Help > About Thunderbird Beta > Release Notes in Thunderbird, or visit Beta release notes.
• Submit all crash reports.
• Check the Beta Start Page which has handy information, available insde Thunderbird with ALT > Go > Mail Start Page (keyboard shortcuts).

Add-ons

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

How to install and run beta

Install Thunderbird Beta into its own program directory, which official Mozilla downloads should do correctly. But be cautious - pay attention that the installer does not target a non-beta program directory - if it does then Thunderbird beta may use and corrupt your production data profile.

For Windows the default install directory is C:\Program Files\Mozilla Thunderbird Beta. If you need more help please refer to installation instructions for Windows, macOS, Linux, and official sources for additional details.

Quick links to official beta sources:

• Windows, macOS and Linux via Thunderbird download page - choose the beta channel
• Ubuntu from Canonical via Snap -- sudo snap install thunderbird --channel=monthly/beta
• Flatpak

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

Do not change from beta to release by installing release into the beta program folder, nor by pointing a release install to a Thunderbird beta data profile - accessing data with an older version number of the program risks instability and corrupt data.

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

• For POP and local mail: In the Mail directory of your Thunderbird profile you will find both 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. HOWEVER, NOTE, 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 files from a beta profile to your production profile.

Beta 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.