Thunderbird didn't support the top level domain like .academy.
I had a problem to add mail account. Thunderbird said Double check this email address. It seems like Thunderbird doesn't support Top Level Domain like .academy. Help me to fix this issues.
Wšykne wótegrona (1)
It looks like there is a restriction in the Thunderbird code that limits the last part of the address to maximum 6 characters, so at the moment it is not possible to use addresses like: .academy .accountant .airforce .apartments etc...
I've filed a bug for this issue, so I hope it will be fixed in a future version of Thunderbird: Bug 1379976 - New Mail Account wizard doesn't allow setup of .academy mail address
Maybe you can try manual setup and see if that works for now?
Wót Onno Ekker