I have been browsing around trying to find the answer to this but I am not having any luck. I want to add the users email to the table so that we can identify them easier. I have tried to create a new page and use "/admin/people" as the path but I get the error that it can not be overridden. I am relatively new to Drupal so if it sounds like a noob question that is why.
Have you tried using Views for this? This will work well if you want to make a new page that lists all of the users. It won't work out of the box if you want to add the email information to the existing admin/people overlay.
- To use Views, enable the module and go to admin/structure/views/add
- Give the View a name, and then for the 'Show:' option from the dropdown select 'Users'
- To create a new page, leave the 'create a new page' item checked, give the new page a title and path, and under Display Format select 'Fields' Hit Continue and Edit
- On the next screen under Fields hit the Add button, and select User:email
There are tons of options to configure with Views - check out the Views Documentation for more information if you're new to Views.
Similiar to @kbrinner answers, I recommend installing the Admin Views module.
Replaces administrative overview/listing pages with actual views for superior usability.
By doing this you can then edit the People view and add the email column for all users.