Customize Signup Notification Emails

The confirmation emails that are sent to us after a volunteer signs up are too generic and the format is not able to be edited by us. We are a community garden organization and our staff is out in the field so it's rarely an option to be able to login to a computer to access volunteer information. We need a quick snapshot to know when and where a volunteer has signed up and how to quickly get in touch should an opportunity be cancelled, etc. We would like the confirmations to be more specific to include the date, time, volunteer name, and phone number. Thank you for considering this!