Thunderbird 68.0

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 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 68.0 changelog:

What’s new:

File link attachments can now be linked to again instead of uploading them again
Mark all folders of an account as read
Run filters periodically. Improved filter logging.
OAuth2 authentication for Yandex
Language packs can now be selected in the Advanced Options. Preference intl.multilingual.enabled needs to be set (and possily also extensions.langpacks.signatures.required needs to be set to false)
On Windows a 64bit installer and MSI package are now available, see the Thunderbird for Organisations page for details
Added a policy engine that allows customized Thunderbird deployments in enterprise environments, using Windows Group Policy or a cross-platform JSON file
TCP keepalive for IMAP protocol
Full Unicode support for MAPI interfaces: New support for MAPISendMailW
To protect your profile data against a downgrade, Thunderbird 68 may display a message "You have launched an older version of Thunderbird" and will not allow opening a specific profile. Workaround: start with option --allow-downgrade. See this support article for details.
Calendar: Time zone data can now include past and future changes. All known time zone changes from 2018 to 2022 are included.
Chat: In each conversation an individual spellcheck language can be selected now
Add-on support: Add-ons are only supported if add-on authors have adapted them

Changed:

Dictionary support: Only WebExtension dictionaries are supported now. Both addons.mozilla.org and addons.thunderbird.net now provide WebExtension dictionaries.
Theme support: Only WebExtension themes are supported now. Both addons.mozilla.org and addons.thunderbird.net now provide WebExtension themes.
The stand-alone options window has been removed, all options are now shown in a tab
Changed UI when installing add-ons
Various theme improvements including a dark message list/thread pane
Application menu aka "Hamburger menu"
Improvements when entering, selecting and removing recipients in the Write window
FileLink: WeTransfer is already included. Dropbox and Box.com using the new WebExtensions FileLink API are available as add-ons, amongst others.
Text and background colors in the Write window and custom colors for tags are no longer restricted to a fixed 10x7 matrix of HTML colors
Composition text and background colors no longer sent by default. New option in "Tools > Options, Composition".
UI improvements for external and detached attachments, now showing as links with new menu option "Open Containing Folder"
Improved phishing attempt detection for messages with certain forms
Improvements to scam warnings
Reply to self will now search all identities (default of preference mailnews.reply_to_self_check_all_ident changed to true)
Maildir now uses the message ID as file name and "eml" as file extension
Auto-compact threshold increased from 20 MB to 200 MB
Calendar: UI improvements for event dialog
Calendar: Thunderbird's calendar add-on Lightning now uses the same version numbering scheme

Fixed:

Column choice and sort order in "Search Messages" dialog lost after relaunch
Global indexer causing high CPU loads under some circumstances
Tags set on IMAP folders sometimes not visible to other users
SMTP password wasn't removed when account was deleted or server or user name were changed
Mbox to Maildir conversion not working if Windows search integration is enabled
Mails won't get removed from Trash folder using Maildir. Note: Other deletion issues related to Maildir may still persist.
When sending of a message failed due a security issue, only "unknown error" was displayed. Now more details are given.
Improvements of SMTP 5.7.1 message
Calendar: Multiple connections with different users to the same CalDAV server not working
Chat: Fixed XMPP authentication when using SASL