Let me help you fix it, Stardancer1964.

You can find the email address on the customer's profile. 
 

In your case, you're unable to see the info on their profile. You're probably experiencing some browser hiccups. Let's perform some basic troubleshooting. We'll start by opening QuickBooks Online through an incognito window. It's the best place to identify web issues. These are the shortcut keys:

• Google Chrome: press Ctrl + Shift + N 
• Mozilla Firefox: press Ctrl + Shift + P
• Safari: press Command + Shift + N

If you're able to see the email address field and delete the info, go back to your regular browser, then clear the cache to refresh the account. It's advisable to clear them out periodically to prevent browser issues. 

Moreover, you can use a different browser to help us narrow the cause of this behavior.

I'll also share the article on how to add, delete, merge, and restore customers as a future reference: Manage your customer list.

You can keep us updated after trying the recommended steps. We're just around to help you.