When logging in, confirm you are using the correct details.
FTP uses the user's account (the one issued to you upon product activation) or an account you issued yourself.
Mail requires the email and password to be correct (and/or the SMTP server on email clients) - you will not receive email if you use CloudFlare proxying on the mail record.
MySQL requires you to login with an account you made whilst adding a database, you cannot login with your usual account.