Hi petersladdie thanks for posting although we're sorry to hear of the concerns you've raised.
As you've mentioned wanting to access Blueyonder email via My Virgin Media, you would need to have a third party email registered as your My Virgin Media username.
The full steps are here:
Click on Account settings > Virgin Media Mail settings > scroll down to the App password section and click the Generate new App password button.
You should get a pop up message asking you to verify your email address and you'll need to use a 3rd party email address to continue. You'll be sent a one time passcode to enter on the next page to verify it's you. Once verified you'll then be given an app password which will look something similar to: mail-horse-yellow-panda and you should note this down.
To get things working on an email client or app again, you will need to enter the new mail password in the settings. This will allow your emails to load again. In some cases, you may need to remove the email account from the mail client or app completely and re-set it up as fresh. If this is the case for you, please ensure you use your VM email address as the username and the newly generated app password.
These changes have been put in place as Multi-factor authentication (MFA) is now required. Just as a side note, when logging in to My VM, you will need to use the third party email address as the username and your original My VM password.
Once this is done, you should then use the third party email address to sign into My Virgin Media, and access your Blueyonder emails.
We hope this helps.