Betterbird. Simply better.

Betterbird is a fine-tuned version of Mozilla Thunderbird, Thunderbird on steroids, if you will.

Betterbird is better than Thunderbird in three ways: It contains new features exclusive to Betterbird, it contains bug fixes exclusive to Betterbird and it contains fixes that Thunderbird may ship at a later stage. Please refer to this feature table for examples. This should give you an impression of where the project is headed. More information on why we're doing the project can be found at the FAQ.

Betterbird 91.0 released on 5th August 2021

Today we are shipping the first release "bb8" of Betterbird version 91. In a successful beta period of Betterbird, we shipped the first beta release "bb1" on 12th July 2021, the last beta release "bb7" on 2nd August 2021. Please refer to the release notes for details.

Betterbird 91.0.1 released on 17th August 2021

Today we are shipping Betterbird version 91.0.1-bb9. We are proud to make the first localisation into German available. Please refer to the release notes for details.

Betterbird 91.2.1 released on 19th October 2021

Today we are shipping Betterbird version 91.2.1-bb17. Please refer to the release notes for details. This includes "regular" (not global) search and Quick Filter for encrypted messages.

Other news

For the much requested multi-line view, see here for details.

Examples of Betterbird being better in version 91.2.1-bb17

FeatureBetterbirdThunderbird
Features exclusive to Betterbird
Multi-line view like in Outlook, Lotus Notes and Postbox Yes!Requested since 2003
Can customise the header pane buttons Yes!No, feature deliberately removed
Quick Filter untagged messages Yes!Development stalled since 2016
Permanently decrypt messagesYes!Not working since version 78
Global search in encrypted messagesYes!Not working :-(
Quick Filter search in encrypted messagesYes!Not working
Windows systray icon New messages count and folder listNew messages count
Printing the selectionYes! Preview here. Quote: "this cannot be fixed"
Activity ManagerOpens in tabOpens in stand-alone window
Bug fixes so far exclusive to Betterbird(*)
Opening an attachmentFineKeeps asking what to do
Inserting links with spacesFineRandom incorrect results
View > Repair Text EncodingWorkingNew feature and broken already
Add search engine via XML fileWorkingBroken since version 87 beta

Of course the Thunderbird team is busily adding a whole bunch of much welcomed new stuff and improvements, but making sure that everything remains in working order falls by the wayside. Thunderbird is shipped with unnecessary regressions, so things that used to work stopped working.
(*) We supply our changes to Thunderbird, but it is unclear if/when "upstream" will accept them.