Thunderbird not working with iCloud

[jwolf6589]

I have not used Thunderbird in ages but today decided to use it again and now I can no longer send email with my iCloud account. It says I need to re-enter my password and every time I do it just continues to ask me to re-enter my password. Server settings (outgoing/incoming) are correct so there is something else I am not doing. I tried a google search and it was not very helpful at all so I seek advice from others using Thunderbird on the Mac.