When using a password longer than 16 characters, Thunderbird fails to login to the smtp outgoing live/outlook server.
The problem persists after disabling my AV, turning off my VPN, starting Thunderbird in safe mode, and even after adding a "1" to the end of my 16ch password.
Interestingly, Microsoft has the following warning when changing your password: Warning: Passwords longer than 16 characters cannot be used with the Xbox 360
See attached screenshots.