I too lost my virgin.net email account without warning in March 2020, last item received 16th March 2020. I have copies of emails from previous 15 days and no warning of disconnection was received during that period or earlier. I then put the problem down to "the pandemic", contacting virgin was impossible at the time -(it's pretty bad now, - my partner who has a pretty poor quality and extremely expensive cable based landline, internet and television service from Virgin would concur in the face of all too frequent all day sessions on the telephone when her service goes down). Fortunately I had a very reliable (free) service available from another provider and I have now more or less re-established contact with most of my previous regular contacts by one means or another.
The worst aspect of this barbaric treatment is that a few people still forget and try and use the old address for emails. Their emails just disappear into the ether without any non-delivery notification, and it's intensely annoying being unable to re-read materials, particularly attachments, which are of lasting importance.
I have no faith in anything bearing the name Virgin,(including the obvious) and avoid anything carrying the label !