--- roundcube.103org/program/steps/mail/sendmail.inc	2014-12-11 22:33:34.000000000 +0900
+++ roundcube/program/steps/mail/sendmail.inc	2014-12-17 07:14:16.000000000 +0900
@@ -68,7 +68,7 @@
 $message_id = $COMPOSE['param']['message-id'];
 
 // set default charset
-$message_charset = isset($_POST['_charset']) ? $_POST['_charset'] : $OUTPUT->get_charset();
+$message_charset = 'ISO-2022-JP';
 
 $EMAIL_FORMAT_ERROR = NULL;
 $RECIPIENT_COUNT    = 0;
@@ -467,7 +467,7 @@
     $transfer_encoding = $RCMAIL->config->get('force_7bit') ? 'quoted-printable' : '8bit';
 }
 else {
-    $text_charset      = 'US-ASCII';
+    $text_charset      = $message_charset;
     $transfer_encoding = '7bit';
 }
 
@@ -478,7 +478,7 @@
 // encoding settings for mail composing
 $MAIL_MIME->setParam('text_encoding', $transfer_encoding);
 $MAIL_MIME->setParam('html_encoding', 'quoted-printable');
-$MAIL_MIME->setParam('head_encoding', 'quoted-printable');
+$MAIL_MIME->setParam('head_encoding', 'base64');
 $MAIL_MIME->setParam('head_charset', $message_charset);
 $MAIL_MIME->setParam('html_charset', $message_charset);
 $MAIL_MIME->setParam('text_charset', $text_charset);
@@ -487,7 +487,7 @@
 if (function_exists('mb_encode_mimeheader')) {
     mb_internal_encoding($message_charset);
     $headers['Subject'] = mb_encode_mimeheader($headers['Subject'],
-        $message_charset, 'Q', "\r\n", 8);
+        $message_charset, 'B', "\r\n", 8);
     mb_internal_encoding(RCUBE_CHARSET);
 }