Index: program/lib/Mail/mime.php
===================================================================
--- program/lib/Mail/mime.php	(revision b517af4a471283adc62ef82cb30b97e896bb6799)
+++ program/lib/Mail/mime.php	(revision 5a6ad209837a8bcca14d4f74541d8ac3ea760341)
@@ -837,7 +837,7 @@
                         // quoted-printable encoding has been selected
                         $mode = 'Q';
-                        $encoded = preg_replace('/([\x20-\x25\x2C\x80-\xFF])/e', "'='.sprintf('%02X', ord('\\1'))", $value);
+                        $encoded = preg_replace('/([\x2C\x3F\x80-\xFF])/e', "'='.sprintf('%02X', ord('\\1'))", $value);
                         // replace spaces with _
-                        $encoded = str_replace('=20', '_', $encoded);
+                        $encoded = str_replace(' ', '_', $encoded);
                     }