E-mail generated has bad From: header

This could be due to my use of the mimemail module in conjunction with this module but I cannot be sure.

When the following mail is generated the From: line in the headers does not display correctly:

user_name,
Congratulations! You now have 1268 fan points on xxx.com.
Thanks for your support and contributions to the site.
Site Admin

The from line reads: From: xxxxx@xxx.com Reply-to: xxxxx@xxx.com X-Mailer: Drupal Return-path: xxxxx@xxx.com Errors-to: xxxxx@xxx.com

This seems to be caused by these lines in the code in function _userpoints_email_process :

    $from = variable_get('site_mail', ini_get('sendmail_from'));
    $headers = "From: $from\nReply-to: $from\nX-Mailer: Drupal\nReturn-path: $from\nErrors-to: $from";

    drupal_mail('userpoints_email',
      $user->mail, $subject, t(variable_get(USERPOINTS_EMAIL_TEXT, USERPOINTS_EMAIL_TEXT_DEFAULT),
      array('!username' => $user->name, '!points' => $current_points)),
      $headers);
  }

I changed the $headers to read:

$headers = "$from";

and this remedied the problem.