changing zoho.adminuserid

Hi
I've never worked out how to ask for help on zoho so posting it here. I want to change hte email address of the 'from' - it currently comes from my main email address and I want to change it. I've tried adding another email to my account (the one that owns the application) and setting this as 'primary' but all emails that are sent from zoho still come from the original email. Any ideas?

the application is kingsarmsnewcomers and it's shared with support.
thanks
Simon
simon