Thunderbird is a free and open source cross-platform email client, personal information manager, news client, RSS and chat client developed by the Mozilla Foundation. The project strategy was originally modeled on the Mozilla Firefox web browser.

On January 28, 2020, the Mozilla Foundation announced that the project will henceforth be run by a new wholly owned subsidiary, MZLA Technologies, to explore offering previously unattainable products and services, collected through partnerships and non-charitable donations income.

Thunderbird 102.3 is released with the following updates:

System Requirements

• Windows: Windows 7 or later
• Mac: macOS 10.12 or later
• Linux: GTK+ 3.14 or later

Variety

• Thunderbird will no longer attempt to import account passwords when importing from another Thunderbird profile, preventing profile corruption and permanent data loss.
• Devtools performance profiles will use Thunderbird presets instead of Web Developer presets

repair

• Improved Thunderbird startup performance
• Failed to save email source and image
• Repeated error message when temp disk space is full
• When attaching an unsized OpenPGP key to an unencrypted message, it briefly shows a size of zero bytes
• Global search entry box initially contains “undefined”
• Deleting mail filtering rules from POP server sometimes fails to trigger
• Failed to connect to POP3 server that does not support UIDL
• “File->New->Address Book Contact” in the mail editing window does not work
• Fixed “My vCard” option not available in mail edit window
• Improved performance for matching contacts to email addresses
• Fixed an issue where Contacts could only recognize the first two email addresses of contacts
• Fixed an issue where address book search and autocompletion failed if the contact’s VCard could not be parsed
• Failed to download NNTP information for offline use
• The NNTP client is stuck when connecting to the Public-Inbox server
• Various visual and user experience improvements
• Various security issues fixes

Known Issues

• There is no dedicated “Department” field in the address book

For more details, please check: https://www.thunderbird.net/en-US/thunderbird/102.3.0/releasenotes/