Send a normal email to
nature@beaconcameraclub.co.uk. That email account is set up to send emails on to Simon.
It does depend what you meant when you said 'it did not work'. Previously, I was getting emails back with the subject 'Delivery Status Notification (Failure)' and containing the error message 'Address not found '. My message to that address did get through last night, but if you got this error message, then it shows that something is still not right - though what that something is is still a puzzle.
If, on the other hand, you wanted to email everyone in the group, I think you'd have to set up a mailing list yourself - or email Simon and ask him to send it out to everyone.