by George Whittaker The Thunderbird team has officially released Thunderbird 156, bringing another round of new features, security improvements, authentication enhancements, and reliability fixes to the popular open-source email client. Released on September 15, 2026, the update is available for Linux alongside Windows and macOS. Thunderbird 156 is not a dramatic redesign of the desktop mail client. Instead, it concentrates on improving areas that matter to everyday users and system administrators, including OAuth authentication, OpenPGP, POP3, IMAP, Exchange Web Services, SMTP, attachments, calendars, enterprise policies, and security. For Linux users in particular, the release delivers several fixes affecting common mail protocols and account configurations while retaining support for Linux environments using GTK+ 3.14 or newer. Thunderbird 156 Arrives on Linux Thunderbird 156 follows version 154, which arrived in August with features including optional system tray operation and Micr