For example, I have the following table:

| comment_ID     | comment_author   | comment_author_email
| -------------- | ---------------- | ---------------------- |
| 100            | Max              | [email protected]          |
| 101            | Max              | [email protected]         |
| 102            | Pierre           | [email protected]       |
| 103            | Max              | [email protected]          |

The result / output of my SQL request should be:

Max: 2
Max: 1 /* because of the different email */
Pierre: 1

My problem:
With the following SQL request, I can get the count of one specific user (the logged-in user):

global $wpdb;
$count = $wpdb->get_var('
SELECT COUNT(comment_author)
FROM ' . $wpdb->comments. '
WHERE comment_author_email = "' . get_comment_author_email() . '"');
echo $count . ' comments';

BUT: How to get the count of all comments per user (by name + email), instead of only the logged-in one?