IMAP Login failing

Dear,

I've created another user email and:
- webmail login is working (user/pwd)
- thunderbird login in not working:
      - all configurations are ok (I have another user configured in the same Thunderbird)
      - pwd is the same that works in the webmail
      - Notification = You are yet to enable IMAP for your account.
What should I do?

Thanks

Paulo