“It’s basically a complete redesign of how you add accounts (like email, calendars, etc.) in Thunderbird. The old setup system worked, but it looked a bit dated, could be confusing with its tab-based approach (easy to accidentally close!), and wasn’t very consistent across different account types.

The Account Hub aims to fix all that. It provides a single, unified, modern-looking wizard inside a pop-up window (modal) to guide you through setup. For brand new users, this modal will guide them without letting them get lost before their first account is ready.”