email client · Betterbird project

Betterbird

Open-source fork of Thunderbird with extra mail-list features, free to download for Windows, Mac and Linux.

78/100

#2 of 10 email clients
Facts checked 8 Oct 2026

In short

The download pages show no price; the project asks for donations⁷.
A Windows installer and a portable zip are offered, plus Mac and Linux builds².
The latest release, 153.4.0esr-bb10, is dated 29 September 2026².
Source code is under the Mozilla Public License 2.0⁸.
The project says it sends no telemetry or crash reports, and mail goes only to your own servers⁶.

Betterbird suits people who like Thunderbird and want extra list, search and layout options without paying anything^1,7. It is open source and says it collects no telemetry^6,8. The catch: its own pages say little about account types, Gmail or Microsoft sign-in, and Exchange, which are inherited from Thunderbird, and it has no phone app^2,4,5.

Best for: Thunderbird users who want more control over how mail is listed, sorted and searched.

Where the points come from

Mail and accounts15 of 27

Calendar and contacts9 of 9

Privacy and encryption24 of 28

Systems and upkeep9 of 15

Price21 of 21

Mail and accounts 15 of 27 points

Rule	What is published	Points
Account types	IMAP, POP3Support page lists IMAP and POP accounts; Exchange and Google or Microsoft sign-in are not documented^4,3.	6 / 12
Unified inbox	YesSupport and expert-tips pages describe unified folders that combine mail^4,5.	4 / 4
Mail tools	TemplatesRelease notes mention 'Reply with Template' and a template folder. No other listed tool is documented³.	2 / 8
Filters and rules	YesSupport page refers to Tools > Message Filters; release notes mention the Filter Editor^4,3.	3 / 3

Calendar and contacts 9 of 9 points

Rule	What is published	Points
Built-in calendar	YesRelease notes cover calendar item descriptions and the expert-tips page covers calendar alarm dialogs and event settings, so the app has a built-in calendar^3,5.	6 / 6
CalDAV and CardDAV	YesSupport page lists CalDAV calendars and CardDAV address books among online services a user may have configured in the app⁴.	3 / 3

Privacy and encryption 24 of 28 points

Rule	What is published	Points
OpenPGP	YesHome page lists search in PGP-encrypted messages; expert tips list OpenPGP settings^1,5.	7 / 7
S/MIME	YesHome page lists global search in S/MIME-encrypted messages, so S/MIME mail is handled in the app¹.	6 / 6
Blocks tracking pixels	Not publishedNot published on the vendor's release notes, support or expert-tips pages^3,4,5.	0 / 4
Open-source apps	YesSource is under the Mozilla Public License Version 2.0, per the LICENSE file in the project repository and the legal page^8,6.	6 / 6
Mail stays on your device	YesLegal page says Betterbird only sends mail you write, not to Betterbird or Mozilla servers⁶.	5 / 5

Systems and upkeep 9 of 15 points

Rule	What is published	Points
Other systems	macOS, LinuxDownloads page lists Mac disk images and a Linux archive; no iOS, Android or web version².	4 / 10
Released in the last year	YesDownloads page shows Windows release 153.4.0esr-bb10 dated 29 September 2026².	5 / 5

Price 21 of 21 points

Rule	What is published	Points
No ads in the app	YesOpen-source app under the Mozilla Public License 2.0⁸.	3 / 3
Free plan	YesOpen-source download with no price shown; the donate page asks for donations. Read as free^7,2.	6 / 6
Cost of a year	$0No price is charged on the vendor's pages; the full app is a free download^2,7.	12 / 12

The rule behind each line: how we score email clients.

Plans and prices

As the vendor lists them, before tax. Prices are in US dollars unless the plan shows euros; the points use US dollars, with euros converted at the ECB rate.

Plan	Price as listed	Per month	Notes
Free1 person	Free^2,7	$0	No price shown; the project asks for donations

Strengths

Free to download, with the source under the Mozilla Public License 2.0^7,8.
Windows installer and portable zip, plus Mac and Linux builds².
Reads and writes Thunderbird profiles, so you can switch back and forth⁴.
Says it sends no telemetry or crash reports to the project⁶.
Names IMAP, POP, filters, unified folders, CalDAV and CardDAV, OpenPGP and S/MIME in its pages^1,3,4,5.

Limits

No iOS, Android or web version is listed².
Mac builds are not notarised, so you must run a command before opening them².
Windows support covers Windows 10 and 11 only⁹.
Exchange calendars need the TbSync add-on; direct Exchange mail support is not documented⁵.
Pages do not document scheduled send, snooze, undo send or blocking of tracking images^3,4,5.

What Betterbird project says

Vendor claims. We show them, but they earn no points.

Betterbird says it is 100% compatible with Thunderbird ESR of the same version⁴.

Other email clients

1
Mozilla ThunderbirdPeople who want a free, open-source client with built-in encryption
88/100
$0cost of a year
3
BlueMailPeople who want a free app with PGP, a calendar and many accounts
78/100
$0cost of a year
4
eM ClientPeople who want PGP, S/MIME and a calendar in one paid Windows app
73/100
$55.87/yrcost of a year
5
Microsoft OutlookPeople who want a free app with a calendar, scheduled send and undo send
67/100
$0cost of a year

Betterbird vs Mozilla Thunderbird · Betterbird vs BlueMail · All 10 email clients

Sources

Betterbird, Betterbird project. Accessed 8 Oct 2026.
Betterbird downloads, Betterbird project. Accessed 8 Oct 2026.
Betterbird release notes, Betterbird project. Accessed 8 Oct 2026.
Betterbird support, Betterbird project. Accessed 8 Oct 2026.
Betterbird expert tips, Betterbird project. Accessed 8 Oct 2026.
Betterbird legal, Betterbird project. Accessed 8 Oct 2026.
Donate to Betterbird, Betterbird project. Accessed 8 Oct 2026.
Betterbird/thunderbird-patches LICENSE, GitHub. Accessed 8 Oct 2026.
Betterbird system requirements, Betterbird project. Accessed 8 Oct 2026.

Website: www.betterbird.eu · Markdown version · We are not affiliated with Betterbird project.