I'm in a similar situation.. was able to log in to main VM website, but when I hit the [Email] button where I'd normally access my ntlworld email, then just got a message to say Email account unavailable.

Been on with the VM Support via Web Messaging service today.. and they say that the domain is no longer supported and that I don't have any means of accessing emails in my ntlworld account.

Anyone sending me an email doesn't get a 'bounce back - account unavailable' message, and I have many online accounts using the defunct ntlworld email address as login and contact for email.  My ntlworld email has also been targeted by hackers, so I would have been receiving messages alerting to password resets etc.. Won't even be aware of these now.

Pretty diabolical customer service from VM.  Not even the decency to provide any advanced notice of this change is service.

Have also been a loyal customer for 25+ years!!!