1) Either R or a local admin created a dynamic distribution list - I have no clue how the query was formed and I'm not about to test it but it included a lot, if not all, of the users on NHSmail
2) I don't believe it was, all of the replies I received were sent to the distribution list - if you still have the mail I'd check again, I don't think there is anything more sinister than a user error enabled by a poorly designed feature.
Biting the hand that feeds IT
