Thank you for your swift reply.? I've appended my response to your original message.
-- Is this moderator on the reverification list? If so, it stands to reason she would receive two copies...one the original and one the bcc. No.
-- Were you unable to contact everyone with a single message and had to do it twice? If so, then this moderator would receive two bcc's. Yes and approximately 40% of the messages were 'qued for delivery'
Does this assist?? I'm not overly concerned hoping its a one-off.
Kind regards