[Velocd]

I've done similar to this, but instead applied it to the 'user prune' page, so you can mass erase those users if need be.

It's funny to see how many users under 'waiting for email verification' have invalid emails.

To do as I've done, just find in admin/user.php:

PHP Code:

echo "<tr class='".getrowbg()."' align='center'>
                <td><font size='1'><b>ID</b></font></td>
                <td><font size='1'><b>Username</b></font></td>
                <td><font size='1'><b>Email</b></font></td>
                <td><font size='1'><b>Posts</b></font></td>
                <td><font size='1'><b>Last Visit</b></font></td>
                <td><font size='1'><b>Join Date</b></font></td>
                <td><input type='checkbox' name='allbox' onclick='CheckAll()' title='select/deselect all' checked></td>
            </tr>\n";
            while ($user = $DB_site->fetch_array($users)) { 


And below it place:

PHP Code:

list($username, $maildomain) = split("@", $user['email']);
                      if (!checkdnsrr($maildomain, "MX"))
                   {
                       $user[email] .= "</a> <font color=\"red\">[<b>invalid email</b>]</font>";
                   } 


It would also make sense to apply this MX lookup to the registration page, to kill the problem at the root.