diff --git a/plugins/managesieve/lib/Roundcube/rcube_sieve_script.php b/plugins/managesieve/lib/Roundcube/rcube_sieve_script.php
index 228213bee..e026f3e5f 100644
--- a/plugins/managesieve/lib/Roundcube/rcube_sieve_script.php
+++ b/plugins/managesieve/lib/Roundcube/rcube_sieve_script.php
@@ -39,6 +39,7 @@ class rcube_sieve_script
         'imap4flags',               // RFC5232
         'include',                  // RFC6609
         'index',                    // RFC5260
+        'mime',                     // RFC5703 (except: foreverypart, break, enclose, extracttext)
         'notify',                   // RFC5435
         'regex',                    // draft-ietf-sieve-regex-01
         'reject',                   // RFC5429
@@ -235,8 +236,11 @@ class rcube_sieve_script
                         break;
 
                     case 'exists':
-                        $tests[$i] .= ($test['not'] ? 'not ' : '');
-                        $tests[$i] .= 'exists ' . self::escape_string($test['arg']);
+                        $tests[$i] .= ($test['not'] ? 'not ' : '') . 'exists';
+
+                        $this->add_mime($test, $tests[$i], $exts);
+
+                        $tests[$i] .= ' ' . self::escape_string($test['arg']);
                         break;
 
                     case 'header':
@@ -248,6 +252,10 @@ class rcube_sieve_script
                         $tests[$i] .= ($test['not'] ? 'not ' : '');
                         $tests[$i] .= $test['test'];
 
+                        if ($test['test'] == 'header') {
+                            $this->add_mime($test, $tests[$i], $exts);
+                        }
+
                         $this->add_index($test, $tests[$i], $exts);
                         $this->add_operator($test, $tests[$i], $exts);
 
@@ -264,7 +272,8 @@ class rcube_sieve_script
                         $tests[$i] .= ($test['not'] ? 'not ' : '');
                         $tests[$i] .= $test['test'];
 
-                        if ($test['test'] != 'envelope') {
+                        if ($test['test'] == 'address') {
+                            $this->add_mime($test, $tests[$i], $exts);
                             $this->add_index($test, $tests[$i], $exts);
                         }
 
@@ -437,6 +446,21 @@ class rcube_sieve_script
                         $action_script .= self::escape_string($action['name']) . ' ' . self::escape_string($action['value']);
                         break;
 
+                    case 'replace':
+                        array_push($exts, 'mime');
+                        $action_script .= 'replace';
+                        if (!empty($action['mime'])) {
+                            $action_script .= " :mime";
+                        }
+                        if (!empty($action['subject'])) {
+                            $action_script .= " :subject " . self::escape_string($action['subject']);
+                        }
+                        if (!empty($action['from'])) {
+                            $action_script .= " :from " . self::escape_string($action['from']);
+                        }
+                        $action_script .= ' ' . self::escape_string($action['replace']);
+                        break;
+
                     case 'notify':
                         array_push($exts, $notify);
                         $action_script .= 'notify';
@@ -799,8 +823,9 @@ class rcube_sieve_script
                 break;
 
             case 'exists':
-                $tests[] = array('test' => 'exists', 'not' => $not,
-                    'arg'  => array_pop($tokens));
+                $test = array('test' => 'exists', 'not' => $not, 'arg'  => array_pop($tokens));
+                $test += $this->test_tokens($tokens);
+                $tests[] = $test;
                 break;
 
             case 'true':
@@ -907,6 +932,15 @@ class rcube_sieve_script
                 $result[] = $action;
                 break;
 
+            case 'replace':
+                $action  = array('type' => 'replace', 'replace' => array_pop($tokens));
+                $args    = array('mime');
+                $vargs   = array('subject', 'from');
+                $action += $this->action_arguments($tokens, $args, $vargs);
+
+                $result[] = $action;
+                break;
+
             case 'require':
                 // skip, will be build according to used commands
                 // $result[] = array('type' => 'require', 'target' => array_pop($tokens));
@@ -986,6 +1020,31 @@ class rcube_sieve_script
         }
     }
 
+    /**
+     * Add mime argument(s) to the test
+     */
+    private function add_mime($test, &$out, &$exts)
+    {
+        foreach (array('mime', 'mime-anychild', 'mime-type', 'mime-subtype', 'mime-contenttype', 'mime-param') as $opt) {
+            if (!empty($test[$opt])) {
+                $opt_name = str_replace('mime-', '', $opt);
+                if (!$got_mime) {
+                    $out .= ' :mime';
+                    $got_mime = true;
+                    array_push($exts, 'mime');
+                }
+
+                if ($opt_name != 'mime') {
+                    $out .= " :$opt_name";
+                }
+
+                if ($opt_name == 'param') {
+                    $out .= ' ' . self::escape_string($test[$opt]);
+                }
+            }
+        }
+    }
+
     /**
      * Add operators to the test
      */
@@ -1021,25 +1080,31 @@ class rcube_sieve_script
         $result = array();
 
         for ($i=0, $len=count($tokens); $i<$len; $i++) {
-            if (!is_array($tokens[$i]) && preg_match('/^:comparator$/i', $tokens[$i])) {
+            $token = is_array($tokens[$i]) ? null : $tokens[$i];
+            if ($token && preg_match('/^:comparator$/i', $token)) {
                 $test['comparator'] = $tokens[++$i];
             }
-            else if (!is_array($tokens[$i]) && preg_match('/^:(count|value)$/i', $tokens[$i])) {
-                $test['type'] = strtolower(substr($tokens[$i], 1)) . '-' . $tokens[++$i];
+            else if ($token && preg_match('/^:(count|value)$/i', $token)) {
+                $test['type'] = strtolower(substr($token, 1)) . '-' . $tokens[++$i];
+            }
+            else if ($token && preg_match('/^:(is|contains|matches|regex)$/i', $token)) {
+                $test['type'] = strtolower(substr($token, 1));
             }
-            else if (!is_array($tokens[$i]) && preg_match('/^:(is|contains|matches|regex)$/i', $tokens[$i])) {
-                $test['type'] = strtolower(substr($tokens[$i], 1));
+            else if ($token && preg_match('/^:(mime|anychild|type|subtype|contenttype|param)$/i', $token)) {
+                $token = strtolower(substr($token, 1));
+                $key   = $token == 'mime' ? $token : "mime-$token";
+                $test[$key] = $token == 'param' ? $tokens[++$i] : true;
             }
-            else if (!is_array($tokens[$i]) && preg_match('/^:index$/i', $tokens[$i])) {
+            else if ($token && preg_match('/^:index$/i', $token)) {
                 $test['index'] = intval($tokens[++$i]);
                 if ($tokens[$i+1] && preg_match('/^:last$/i', $tokens[$i+1])) {
                     $test['last'] = true;
                     $i++;
                 }
-           }
-           else {
-               $result[] = $tokens[$i];
-           }
+            }
+            else {
+                $result[] = $tokens[$i];
+            }
         }
 
         $tokens = $result;
@@ -1090,8 +1155,9 @@ class rcube_sieve_script
     static function escape_string($str)
     {
         if (is_array($str) && count($str) > 1) {
-            foreach ($str as $idx => $val)
+            foreach ($str as $idx => $val) {
                 $str[$idx] = self::escape_string($val);
+            }
 
             return '[' . implode(',', $str) . ']';
         }