Well firstly the ‘ntlworld email have no server’ is complete rubbish, of course it does, something has to receive and store the email. However, if the email has been deleted then, unfortunately it’s gone, VM don’t retain any backups, (for very good practical and legal reasons), the onus is on you, the customer to keep such backups.
Now having said that, the first thing you need to do is to log into the webmail view of your mailbox at https://mail2.virginmedia.com and see if the emails are there. If not, then I am afraid realistically they’re gone.