"text" is invalid, "text/plain" is what you want.

diff --git a/html/sites/all/modules/moneyscripts/ms_affiliates/ms_affiliates.module b/html/sites/all/mod
index 2385eba..e2fe701 100755
--- a/html/sites/all/modules/moneyscripts/ms_affiliates/ms_affiliates.module
+++ b/html/sites/all/modules/moneyscripts/ms_affiliates/ms_affiliates.module
@@ -1362,7 +1362,7 @@ function ms_affiliates_get_children($uid, $max_depth) {
  */
 function ms_affiliates_mail($key, &$message, $vars) {
   $headers = array(
-    'Content-Type' => 'text; charset=UTF-8;',
+    'Content-Type' => 'text/plain; charset=UTF-8;',^M
     'From' => variable_get('site_name', '') ." <". variable_get('site_mail', '') .">",
     'Reply-To' => variable_get('site_mail', ''),
   );