If you are not a BT Broadband customer or paying for your email through a BT Premium email account your email account will be a BTMail Basic account.
See link.
BT Email products | Types of BT Emails | BT Help
This will only work using a web browser and not with email clients/app such as Bluemail so there is no point in trying to use one.
The fact that you are no longer a BT Broadband customer should not prevent you getting BT help with your BTMail account which is still supplied and managed by BT.
If you are locked out of your account you could try clearing the history and cookies from your web browser. When you do that make sure that you select the option "Clear All Time" if your browser offers that option.
Also if you are using a shortcut to log on try a fresh shortcut such as the Email button in the banner at the top of this page.
If that does not work you will need to call BT 0330.1234.150 and ask to speak to the Email Team. If they say they can not help you ask for a detailed reason why not because you have a BTMail Basic account which is provided by BT and there is nowhere listed that says that BT can not help. If they still insist the can not help ask them to provide where the information regarding that is available to view and ask to speak to a manager.
Take a note of who your speaking to and the time and date along with what was said so that you have that information when you make a formal complaint.
See Terms and Conditions for BTMail. There is no mention of BT not helping BTMail Basic accounts when something goes wrong.
Email terms and conditions
