Hi Markvii 👋 welcome to the community! Thank you for posting.
Sorry to hear you are having some difficulties logging in to your My VM / Email account.
What is likely happening, is the system is prompting you to provide a non NTLworld email address to use as the login. This means if there is any issue with the account you are able to access a password reset / email verification via an alternative account.
You can find a bit more information about this in our help-page for managing your email here 👉 How to manage my email account | Virgin Media Help and for managing your My VM account here 👉 How to manage my account | Virgin Media Help
We also may just need to check everything is set up correctly on our side, so I will send you a PM to confirm a few account details and offer support. You can find the PM in the top right corner of the page in your Inbox. 📩 We can then return to this public thread with another update when possible. Thank you for your patience in the meantime!
Wishing you all the best. 🌞