Hi Rob
Thanks for your help on this, I have changed my 'to' field to [your-recipient] and the email comes through to my test address, but the problem is not that I see the emails in the body, it's that I still see the other email addresses in the 'to' field when it arrives in the inbox.
So using bcc does not seem to work
If a reader of the site selects 2 out of the 4 email addresses from the dropdown that works perfectly, the problem is that when the email comes through to email user 1 they can also see it has been sent to email user 2