diff --git a/program/include/rcmail.php b/program/include/rcmail.php
index 8d0fc1c11..1122152b5 100644
--- a/program/include/rcmail.php
+++ b/program/include/rcmail.php
@@ -50,6 +50,8 @@ class rcmail extends rcube
     public $action    = '';
     public $comm_path = './';
     public $filename  = '';
+    public $default_skin;
+    public $login_error;
 
     private $address_books = array();
     private $action_map    = array();
@@ -207,10 +209,12 @@ class rcmail extends rcube
     {
         $contacts    = null;
         $ldap_config = (array)$this->config->get('ldap_public');
+        $default     = false;
 
         // 'sql' is the alias for '0' used by autocomplete
-        if ($id == 'sql')
+        if ($id == 'sql') {
             $id = '0';
+        }
         else if ($id == -1) {
             $id = $this->config->get('default_addressbook');
             $default = true;
@@ -559,17 +563,20 @@ class rcmail extends rcube
 
         // parse $host URL
         $a_host = parse_url($host);
-        if ($a_host['host']) {
+        $ssl = false;
+        if (!empty($a_host['host'])) {
             $host = $a_host['host'];
             $ssl  = (isset($a_host['scheme']) && in_array($a_host['scheme'], array('ssl','imaps','tls'))) ? $a_host['scheme'] : null;
 
-            if (!empty($a_host['port']))
+            if (!empty($a_host['port'])) {
                 $port = $a_host['port'];
-            else if ($ssl && $ssl != 'tls' && (!$default_port || $default_port == 143))
+            }
+            else if ($ssl && $ssl != 'tls' && (!$default_port || $default_port == 143)) {
                 $port = 993;
+            }
         }
 
-        if (!$port) {
+        if (empty($port)) {
             $port = $default_port;
         }
 
@@ -941,12 +948,13 @@ class rcmail extends rcube
 
             if (function_exists('memory_get_usage')) {
                 $mem = round(memory_get_usage() / 1024 /1024, 1);
-            }
-            if (function_exists('memory_get_peak_usage')) {
-                $mem .= '/'. round(memory_get_peak_usage() / 1024 / 1024, 1);
+
+                if (function_exists('memory_get_peak_usage')) {
+                    $mem .= '/'. round(memory_get_peak_usage() / 1024 / 1024, 1);
+                }
             }
 
-            $log = $this->task . ($this->action ? '/'.$this->action : '') . ($mem ? " [$mem]" : '');
+            $log = $this->task . ($this->action ? '/'.$this->action : '') . (isset($mem) ? " [$mem]" : '');
 
             if (defined('RCMAIL_START')) {
                 self::print_timer(RCMAIL_START, $log);
@@ -1336,10 +1344,12 @@ class rcmail extends rcube
         // strftime() format
         if (preg_match('/%[a-z]+/i', $format)) {
             $format = strftime($format, $timestamp);
-            if ($stz) {
+
+            if (isset($stz)) {
                 date_default_timezone_set($stz);
             }
-            return $today ? ($this->gettext('today') . ' ' . $format) : $format;
+
+            return !empty($today) ? ($this->gettext('today') . ' ' . $format) : $format;
         }
 
         // parse format string manually in order to provide localized weekday and month names
@@ -1378,7 +1388,7 @@ class rcmail extends rcube
             }
         }
 
-        if ($today) {
+        if (!empty($today)) {
             $label = $this->gettext('today');
             // replcae $ character with "Today" label (#1486120)
             if (strpos($out, '$') !== false) {
@@ -1389,7 +1399,7 @@ class rcmail extends rcube
             }
         }
 
-        if ($stz) {
+        if (isset($stz)) {
             date_default_timezone_set($stz);
         }
 
@@ -1423,13 +1433,13 @@ class rcmail extends rcube
         // get current folder
         $storage   = $this->get_storage();
         $mbox_name = $storage->get_folder();
+        $delimiter = $storage->get_hierarchy_delimiter();
 
         // build the folders tree
         if (empty($a_mailboxes)) {
             // get mailbox list
             $a_folders = $storage->list_folders_subscribed(
                 '', $attrib['folder_name'], $attrib['folder_filter']);
-            $delimiter = $storage->get_hierarchy_delimiter();
             $a_mailboxes = array();
 
             foreach ($a_folders as $folder) {
@@ -1461,6 +1471,7 @@ class rcmail extends rcube
             $out = $select->show($attrib['default']);
         }
         else {
+            $out = '';
             $js_mailboxlist = array();
             $tree = $this->render_folder_tree_html($a_mailboxes, $mbox_name, $js_mailboxlist, $attrib);
 
@@ -2028,7 +2039,7 @@ class rcmail extends rcube
             $params['prefix'] = false;
         }
 
-        if ($error) {
+        if (!empty($error)) {
             if ($suffix && $this->text_exists($error . $suffix)) {
                 $error .= $suffix;
             }
@@ -2296,7 +2307,7 @@ class rcmail extends rcube
                     if ($imgtype = $image->resize($thumbnail_size, $cache_file, true)) {
                         $mimetype = 'image/' . $imgtype;
 
-                        if ($orig_name) {
+                        if (!empty($orig_name)) {
                             unlink($orig_name);
                         }
                     }
diff --git a/program/include/rcmail_install.php b/program/include/rcmail_install.php
index ebd23417d..8d80fb113 100644
--- a/program/include/rcmail_install.php
+++ b/program/include/rcmail_install.php
@@ -31,6 +31,8 @@ class rcmail_install
     public $is_post           = false;
     public $failures          = 0;
     public $config            = array();
+    public $defaults          = array();
+    public $comments          = array();
     public $configured        = false;
     public $legacy_config     = false;
     public $email_pattern     = '([a-z0-9][a-z0-9\-\.\+\_]*@[a-z0-9]([a-z0-9\-][.]?)*[a-z0-9])';
@@ -133,6 +135,9 @@ class rcmail_install
             return;
         }
 
+        $config        = array();
+        $rcmail_config = array(); // deprecated var name
+
         include $file;
 
         // read comments from config file
@@ -158,12 +163,7 @@ class rcmail_install
             }
         }
 
-        // deprecated name of config variable
-        if (is_array($rcmail_config)) {
-            return $rcmail_config;
-        }
-
-        return $config;
+        return array_merge(array(), (array) $rcmail_config, (array) $config);
     }
 
     /**
@@ -507,9 +507,10 @@ class rcmail_install
      */
     private function db_read_schema($schemafile, &$version = null)
     {
-        $lines    = file($schemafile);
-        $schema   = array();
-        $keywords = array('PRIMARY','KEY','INDEX','UNIQUE','CONSTRAINT','REFERENCES','FOREIGN');
+        $lines      = file($schemafile);
+        $schema     = array();
+        $keywords   = array('PRIMARY','KEY','INDEX','UNIQUE','CONSTRAINT','REFERENCES','FOREIGN');
+        $table_name = null;
 
         foreach ($lines as $line) {
             if (preg_match('/^\s*create table ([\S]+)/i', $line, $m)) {
diff --git a/program/include/rcmail_output_html.php b/program/include/rcmail_output_html.php
index 2a820e42e..4c995dc6f 100644
--- a/program/include/rcmail_output_html.php
+++ b/program/include/rcmail_output_html.php
@@ -694,6 +694,7 @@ EOF;
     {
         $plugin   = false;
         $realname = $name;
+        $skin_dir = '';
         $plugin_skin_paths = array();
 
         $this->template_name = $realname;
@@ -804,6 +805,7 @@ EOF;
     {
         $out             = '';
         $parent_commands = 0;
+        $parent_prefix   = '';
         $top_commands    = array();
 
         // these should be always on top,
@@ -1439,7 +1441,7 @@ EOF;
                         $key    = 'name';
                         $param  = 'content';
                     }
-                    else if ($object == 'links') {
+                    else {
                         $source = 'link_tags';
                         $tag    = 'link';
                         $key    = 'rel';
@@ -1719,6 +1721,8 @@ EOF;
         }
 
         $out = '';
+        $btn_content = null;
+        $link_attrib = array();
 
         // generate image tag
         if ($attrib['type'] == 'image') {
@@ -1776,7 +1780,7 @@ EOF;
             $out = html::tag($attrib['wrapper'], null, $out);
         }
 
-        if ($menuitem) {
+        if (!empty($menuitem)) {
             $class = $attrib['menuitem-class'] ? ' class="' . $attrib['menuitem-class'] . '"' : '';
             $out   = '<li role="menuitem"' . $class . '>' . $out . '</li>';
         }
@@ -1967,7 +1971,7 @@ EOF;
         }
 
         // add css files in head, before scripts, for speed up with parallel downloads
-        if (!empty($this->css_files) && !$is_empty
+        if (!empty($this->css_files) && empty($is_empty)
             && (($pos = stripos($output, '<script ')) || ($pos = stripos($output, '</head>')))
         ) {
             $css = '';
@@ -2043,6 +2047,8 @@ EOF;
      */
     public function form_tag($attrib, $content = null)
     {
+        $hidden = '';
+
         if ($this->env['extwin']) {
             $hiddenfield = new html_hiddenfield(array('name' => '_extwin', 'value' => '1'));
             $hidden = $hiddenfield->show();
@@ -2168,6 +2174,7 @@ EOF;
         $input_pass   = new html_passwordfield(array('name' => '_pass', 'id' => 'rcmloginpwd', 'required' => 'required')
             + $attrib + $pass_attrib);
         $input_host   = null;
+        $hide_host    = false;
 
         if (is_array($default_host) && count($default_host) > 1) {
             $input_host = new html_select(array('name' => '_host', 'id' => 'rcmloginhost'));
@@ -2304,10 +2311,14 @@ EOF;
         }
 
         if (!empty($attrib['wrapper'])) {
-            $header = html::tag($attrib['ariatag'] ?: 'h2', array(
-                    'id'    => 'aria-label-' . $attrib['label'],
-                    'class' => 'voice'
-                ), rcube::Q($this->app->gettext('arialabel' . $attrib['label'], $attrib['label-domain'])));
+            $options_button = '';
+            $header_label = $this->app->gettext('arialabel' . $attrib['label'], $attrib['label-domain']);
+            $header_attrs = array(
+                'id'    => 'aria-label-' . $attrib['label'],
+                'class' => 'voice'
+            );
+
+            $header = html::tag($attrib['ariatag'] ?: 'h2', $header_attrs, rcube::Q($header_label));
 
             if ($attrib['options']) {
                 $options_button = $this->button(array(
diff --git a/program/include/rcmail_sendmail.php b/program/include/rcmail_sendmail.php
index 503710a1a..e2ac45b9f 100644
--- a/program/include/rcmail_sendmail.php
+++ b/program/include/rcmail_sendmail.php
@@ -31,7 +31,8 @@ class rcmail_sendmail
     public $options = array();
 
     protected $parse_data = array();
-    protected $compose_form;
+    protected $message_form;
+    protected $rcmail;
 
     // define constants for message compose mode
     const MODE_REPLY   = 'reply';
@@ -121,6 +122,7 @@ class rcmail_sendmail
         $from          = rcube_utils::get_input_value('_from', rcube_utils::INPUT_POST, true, $charset);
         $replyto       = rcube_utils::get_input_value('_replyto', rcube_utils::INPUT_POST, true, $charset);
         $followupto    = rcube_utils::get_input_value('_followupto', rcube_utils::INPUT_POST, true, $charset);
+        $from_string   = '';
 
         // Get sender name and address from identity...
         if (is_numeric($from)) {
@@ -177,7 +179,7 @@ class rcmail_sendmail
             'Bcc'              => $mailbcc,
             'Subject'          => trim($subject),
             'Reply-To'         => $this->email_input_format($replyto),
-            'Mail-Reply-To'    => $headers['Reply-To'],
+            'Mail-Reply-To'    => $this->email_input_format($replyto),
             'Mail-Followup-To' => $this->email_input_format($followupto),
             'In-Reply-To'      => $this->data['reply_msgid'],
             'References'       => $this->data['references'],
@@ -370,7 +372,9 @@ class rcmail_sendmail
     public function deliver_message($message, $disconnect = true)
     {
         // Handle Delivery Status Notification request
-        $smtp_opts = array('dsn' => $this->options['dsn_enabled']);
+        $smtp_opts     = array('dsn' => $this->options['dsn_enabled']);
+        $smtp_error    = null;
+        $mailbody_file = null;
 
         $sent = $this->rcmail->deliver_message($message,
             $this->options['from'],
@@ -436,6 +440,10 @@ class rcmail_sendmail
      */
     public function save_message($message)
     {
+        $store_folder = false;
+        $store_target = null;
+        $saved        = false;
+
         // Determine which folder to save message
         if ($this->options['savedraft']) {
             $store_target = $this->rcmail->config->get('drafts_mbox');
@@ -812,8 +820,12 @@ class rcmail_sendmail
     {
         list($form_start,) = $this->form_tags($attrib);
 
-        $out  = '';
-        $part = strtolower($attrib['part']);
+        $out          = '';
+        $part         = strtolower($attrib['part']);
+        $fname        = null;
+        $field_type   = null;
+        $allow_attrib = array();
+        $param        = $part;
 
         switch ($part) {
         case 'from':
@@ -823,7 +835,6 @@ class rcmail_sendmail
         case 'cc':
         case 'bcc':
             $fname  = '_' . $part;
-            $header = $param = $part;
 
             $allow_attrib = array('id', 'class', 'style', 'cols', 'rows', 'tabindex');
             $field_type   = 'html_textarea';
@@ -833,14 +844,12 @@ class rcmail_sendmail
         case 'reply-to':
             $fname  = '_replyto';
             $param  = 'replyto';
-            $header = 'reply-to';
 
         case 'followupto':
         case 'followup-to':
             if (!$fname) {
                 $fname  = '_followupto';
                 $param  = 'followupto';
-                $header = 'mail-followup-to';
             }
 
             $allow_attrib = array('id', 'class', 'style', 'size', 'tabindex');
diff --git a/program/include/rcmail_utils.php b/program/include/rcmail_utils.php
index ca1359355..fced68fd4 100644
--- a/program/include/rcmail_utils.php
+++ b/program/include/rcmail_utils.php
@@ -61,9 +61,10 @@ class rcmail_utils
      */
     public static function db_init($dir)
     {
-        $db = self::db();
+        $db    = self::db();
+        $error = null;
+        $file  = $dir . '/' . $db->db_provider . '.initial.sql';
 
-        $file = $dir . '/' . $db->db_provider . '.initial.sql';
         if (!file_exists($file)) {
             rcube::raise_error("DDL file $file not found", false, true);
         }
@@ -116,7 +117,7 @@ class rcmail_utils
         }
 
         // DB version not found, but release version is specified
-        if (!$version && $ver) {
+        if (empty($version) && $ver) {
             // Map old release version string to DB schema version
             // Note: This is for backward compat. only, do not need to be updated
             $map = array(