diff --git a/lib/util.php b/lib/util.php
--- a/lib/util.php
+++ b/lib/util.php
@@ -263,6 +263,7 @@ if (!function_exists("quoted_printable_e
         function quoted_printable_encode($string) {
             $string = str_replace(array('%20', '%0D%0A', '%'), array(' ', "\r\n", '='), rawurlencode($string));
             $string = preg_replace('/[^\r\n]{73}[^=\r\n]{2}/', "$0=\r\n", $string);
+            $string = preg_replace('/=24SUBJECT/', '$SUBJECT', $string);
             return $string;
         }
     }