Is there any way to stop email from coming without affecting other data services like Internet/Games/Maps/etc?

Like an on/off button, can't seem to find it on the device, using BB8320.

I think you can turn off data services, but not a particular service like email. The only way I know is to delete your service books for your email accounts. Then you'd have to resend them to get email back.

Block email with the firewall.

Remove the email accounts if you use BIS. No other way that I know of.