Have a look at the documentation of mysql_fetch_array.
You need to loop over your results like this:
$result = mysql_query("SELECT DISTINCT wp_users.* FROM wp_users LEFT JOIN (SELECT lead_id, MAX(case when field_number = 7 then value end) AS email, MAX(case when field_number = 8 then value end) AS tournament_id FROM wp_rg_lead_detail GROUP BY lead_id) AS t1 ON t1.email = wp_users.user_email AND t1.tournament_id = '$tournament_id' WHERE t1.lead_id IS NULL AND id !=1");
$replacements = array();
while($user = mysql_fetch_array($result)) {
$replacements[$user['user_email']] = array (
'{user_login}' => $user['user_login']
);
echo $user['user_email'] . "<br />" . $user['user_login'];
}