You need to change the IdentD before connecting to the network, otherwise it won't change. So you need to use /server -n and then /identd on newidenthere, in that order, and then /server again to connect.
If it's not changing, then you may well have a problem with identd so the server is just using your email one regardless - do you have a tilde (~) before your identd when you connect?
Regards,