Thunderbird 146.0

Access all your messages, calendars, and contacts in one fast app. Filter and organize the way you like. Manage all accounts separately or in a unified inbox. Thunderbird simply makes your life simple

Razvan Serea News Reporter Neowin · Dec 9, 2025 23:50 EST with 0 comments

Thunderbird

Thunderbird is a free, open-source, cross-platform application for managing email and news feeds. It is a local (rather than a web-based) email application that is powerful yet easy-to-use.

Thunderbird is clean and elegant by default, but easily customizable to match your workflow and visual preferences. It is loaded with unique and powerful features.

Thunderbird is developed, tested, translated and supported by the folks at Mozilla Corporation and by a group of dedicated volunteers. Thunderbird gives you control and ownership over your email. There are lots of add-ons available for Thunderbird that enable you to extend and customize your email experience.

Thunderbird gives you IMAP/POP support, a built-in RSS reader, support for HTML mail, powerful quick search, saved search folders, advanced message filtering, message grouping, labels, return receipts, smart address book LDAP address completion, import tools, and the ability to manage multiple e-mail and newsgroup accounts.

Thunderbird 146.0 changelog:

What’s new

Enabled configuration of preferred OpenPGP keyserver via the UI

What’s Changed

Existing logins are migrated to make use of more modern AES cryptography

What’s Fixed

Memory was not cleaned up after opening New Window from folder pane context menu
Thunderbird could crash in server subscription logic
Importing a vCard only displayed VCF files in the file picker
Could not distinguish folders with same name in 'Recent Destinations' and 'Favorites'
Could not compose new message if the folder pane was empty
'Delete' was missing from context menu when multiple IMAP folders were selected
'Delete' button in unified toolbar could delete attachments instead of message
'Recent destinations' submenu was not sorted by time of modification
Account column could display incorrect account name
'Tag' submenu of mail context menu could be populated incorrectly
Extending the expiration date of OpenPGP key set incorrect date
Could not sign/encrypt (PGP) when using -compose and Thunderbird was not running
Account Hub email success messages were not always accurate about config source
Account Hub advanced config setup did not include default outgoing config
Account Hub local address book creation could continue with blank name
Detailed security exception dialog was not shown when adding certificate exception
The default account could be reset after restart if uninitialized
Opening a vCard (.vcf) from file manager or CLI did not work in some cases
Dragging attachments on macOS to folder or desktop no longer worked
EWS folder properties "Select this folder for offline use" did not work
Thunderbird could crash when mail folder was renamed or moved
Account Hub could fail when manually creating EWS account
'Offline' folder flag for EWS folders was reset on restart
'Open with' of Microsoft Office attachment did not mark file with MOTW label
Visual and UX improvements
Security fixes