Thunderbird 147.0

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 · Jan 13, 2026 15:14 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 147.0 changelog:

What’s New

Add "Show Full Path" folder pane option for compact view modes
Add `mail.useLocalizedFolderNames' to toggle special folder name localization

What’s Changed

Special folders are now localized based on a restricted set of names

What’s Fixed

Selected status and priority was not displayed in search widgets
Compacting multiple folders failed and did not compact
Resetting manual folder sorting did not work for sub folders
Unified archive subfolders could show wrong names and no messages
Folders with deep hierarchy and long folder names could fail to display
Moving saved search/virtual folder under IMAP could fail
"Open and Show" for OpenPGP-signed message (.eml) did not work
"Search Messages" search did not finish due to unparsable local folders
Compose command line flag no longer worked correctly
Search for "Attachment" in Settings menu did not find "Files and Attachments"
Account Hub did not show error message on failure when creating OAuth2 EWS account
Thunderbird could crash during exchange address account setup
Japanese locale users could not create message filters
Moving virtual folder within maildir based IMAP or local folder could fail
Thunderbird could crash when marking all messages as read
Startup could be slow with large number of folders not using subscriptions
EWS message send that required a password errored instead of prompting
EWS HTTP 500 backoff errors were not handled gracefully
SMTP sending could hang when when multiple messages queued for sending
Thunderbird could crash when emptying EWS trash
Broken feed icon could prevent updating of feeds
Calendar did not alert user for connection issues
Creation of tasks with Start or Due date was not possible
Visual and UX improvements
Security fixes