Thanks for your post, sorry to hear that you are having mailbox issues. What is the error that you are getting? Also how are you attempting to log in, from the website or are you using an app/email client?
Cheers Graham, no didn't see it good shout. Apologies @juliewatson900. I'll have to PM you to get your details and see why the mailbox is coming up as unavailable. If it is an orphaned mailbox [as in not connected to an active Virgin Media account] then I might not be able to re-enable it.