Thunderbird email software's main email interface in Light Mode, showing 3 columns in a "Vertical" layout with new Cards view enabled. The left column shows various accounts and folders, the middle column shows message previews, threads, in various colors and states. The right column shows the full message with header information
https://files.mastodon.online/media_attachments/files/110/668/200/914/893/111/original/c9e218462c7d26c2.png