This is what finally sorted it for me and quickly so thought I'd share (credit to 9fingers as it was their original post I read)
Click here https://my.virginmedia.com/faults/service-status and click on 'live chat' on the right hand side
It's a chat bot initially but just keep typing gobbledygook meaningless replies and press enter (ie/ gdgdggdg or xcxvxvf) and after about 5 or 6 of these it gives up and transfers you to a human agent
You then give them your name and virgin account number and the email address in question and ask them to reset the password at their end. They then ask you to tell them what password you would like it changed to (I just reiterated my original one 🙂 They then reset it at their end and after 30 seconds or so your email should now be working again.
All this took just 8 minutes from my initial enquiry to being fully sorted - hope it helps you too.