The Thunderbird team continues its work on the next big version of the open source email client. Thunderbird 128 Nebula is almost ready and the makers have published a support page that reveals information on the upcoming version.

The main topics covered are:

• Thunderbird Sync
• Exchange support
• Thunderbird 128's ESR label.
• Customization support

Note: It is not 100% clear when Thunderbird 128 will be released. Previous releases were first offered as standalone installers before they were being made available through the program's automatic updating system.

Thunderbird 128: four release channels

Going forward, Thunderbird 128 will be offered in four different versions. These are:

• Thunderbird Daily -- Updates daily with changes similar to Firefox Nightly.
• Thunderbird Beta -- Gets a major update every four weeks and smaller updates for testing before release to stable.
• Thunderbird Release -- The stable version of the email client. Gets major updates every four weeks.
• Thunderbird ESR -- The Extended Support Release version. Gets major updates once a year, minor updates and security updates regularly.

Thunderbird users who do not want to run development versions have the choice between Release and ESR. The main difference is that ESR is getting major changes once per year while Release once per month.

Thunderbird users who want stability over anything else may pick ESR, even though that means that new features will not be available for several releases.

Thunderbird Sync, Exchange support, and customizations

Thunderbird's development team is working on its own synchronization solution. It will likely not be available when Thunderbird 128 is released. The feature allows users to sync data between Thunderbird clients. This allows you, for example, to sync preferences and other customizations.

Regarding Exchange support is available as a pre-beta version. Most organizations and users may want to wait for a final release before they start using it.

Those who do not mind or want to test the functionality may consult the official Thunderbird Exchange support page. It reveals how to enable the functionality in Thunderbird.

In short:

1. Select Menu > Settings > General.
2. Click on Config Editor at the bottom of the page.
3. Search for experimental.mail.ews.enabled.
4. Activate the toggle icon to set the preference to True.
5. Restart Thunderbird.

Exchange accounts may now be added using Thunderbird's "add account" process.

Regarding customization support, the team says that userChrome customizations continue to be unsupported in Thunderbird 128. Some may break and may need to be adjusted.

Closing Words

Thunderbird 128 will be a major release. Most Thunderbird users may want to wait several months before they upgrade to the new version. This helps sort out any bugs that may pop up after release.

Do you use the open source email client or another product? What is your expectation regarding Thunderbird 128? Feel free to leave a comment down below.