Socket error = #10061. 10061 is a Connection Refused error sent to you by the server. You could not make a connection because the target machine actively refused it. The most common cause is a misconfigured server, full server, or incorrect Port specified by the client.
The Generating server i.e. the server sending the bounce message is not one of Virgin Media's servers in this case, it's one of Microsoft's - possibly used for the Office 365 business accounts
What the server is saying is this:
"I've been trying to deliver this message for some time now, but I've given up - the last error message I received was:"
"i.e. The server didn't want to talk to me."
I've paraphrased the message into what I hope is simpler English.
Here's the thing though - I would not expect one of Microsoft's servers to be sending mail from firstname.lastname@example.org, because even if it was forwarding a mail originally received from one of VM's servers, the server itself does not belong to Virgin Media.