State of the Thunder 7: Extended Support Release 140 (and explaining our four channels)

About this episode

The episode discusses the upcoming Thunderbird Extended Support Release 140.0 and explains the different release channels.

In this latest State of the Thunder, we're discussing the upcoming yearly ESR, 140.0, which is due out June 24, 2025. We explain our numbering convention and our different channels, which comes from Firefox, and the difference between ESR, Release, Beta, and Daily. Find out why we're encouraging to use the monthly Release channel, but how this won't take anything away from ESR. Learn more about what channel is right for you (especially if you use add-ons), how to help us with using Beta and Daily, and how to safely move between ESR and Release. And as always, we finish with a community shoutout! Resources: What Train is It Now: http://whattrainisitnow.com Monthly Release Channel Blog Post: https://blog.thunderbird.net/2025/03/thunderbird-release-channel-update/ Choosing a Release Channel: https://support.mozilla.org/kb/choosing-thunderbird-release-channel Testing Beta Support Article: https://support.mozilla.org/kb/thunderbird-beta Testing Daily Support Article: https://support.mozilla.org/kb/thunderbird-daily Release Channel Support Article (with info on safely downgrading): https://support.mozilla.org/kb/thunderbird-release Add-on Compatibility Add-on…

Topics covered

• Extended Support Release
• Thunderbird channels
• Firefox comparison
• Release channel
• Beta and Daily testing
• Add-on compatibility

Keywords

• Thunderbird
• Extended Support Release
• Release channel
• Beta
• Daily
• add-ons
• Firefox

Mentioned in this episode

Organizations: MZLA Technologies Corporation

Products: Thunderbird, Firefox, Add-on Compatibility Add-on

Books & works: What Train is It Now, Monthly Release Channel Blog Post, Choosing a Release Channel, Testing Beta Support Article, Testing Daily Support Article, Release Channel Support Article, tilorenz's Calendar grid patch

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• Bonus Episode: An Android Retrospective · November 14, 2025 · 56 min
• State of the Thunder 13: How the Roadmap Gets Made · October 10, 2025 · 53 min
• State of the Thunder 12: Community, Android, and Mozilla Connect · September 23, 2025 · 40 min