I add reminders to all my calendar events. This is fine when I am online and using the web UI. However, if I am not logged in to the web interface I get an email notification instead. This is undesirable as the pop notification generates a notification on my phone, and any other open calendar client so I always get the reminder - the email has no value to me. 

I cannot delete the email address in Calendar Settings > Preferences > Email Notify, nor can I use a fictitious email address and there is no option to disable. How can I disable this?  Currently I am using a filter to see if I can get rid of the email. My calendar is set to add a pop up reminder for all events.

Thanks

Alan