Merged devel-framework branch (r5746:5779) back into trunk

16 files changed, 178 insertions, 171 deletions

diff --git a/program/steps/mail/check_recent.inc b/program/steps/mail/check_recent.inc
index 498bf0ce1..6673d0c17 100644
--- a/program/steps/mail/check_recent.inc
+++ b/program/steps/mail/check_recent.inc
@@ -19,12 +19,12 @@
 
 */
 
-$current = $RCMAIL->imap->get_mailbox_name();
+$current = $RCMAIL->storage->get_folder();
 $check_all = !empty($_GET['_refresh']) || (bool)$RCMAIL->config->get('check_all_folders');
 
 // list of folders to check
 if ($check_all) {
-    $a_mailboxes = $RCMAIL->imap->list_mailboxes('', '*', 'mail');
+    $a_mailboxes = $RCMAIL->storage->list_folders_subscribed('', '*', 'mail');
 }
 else {
     $a_mailboxes = (array) $current;
@@ -37,11 +37,11 @@ foreach ($a_mailboxes as $mbox_name) {
     $is_current = $mbox_name == $current;
     if ($is_current) {
         // Synchronize mailbox cache, handle flag changes
-        $RCMAIL->imap->mailbox_sync($mbox_name);
+        $RCMAIL->storage->folder_sync($mbox_name);
     }
 
     // Get mailbox status
-    $status = $RCMAIL->imap->mailbox_status($mbox_name);
+    $status = $RCMAIL->storage->folder_status($mbox_name);
 
     if ($status & 1) {
         // trigger plugin hook
@@ -58,7 +58,7 @@ foreach ($a_mailboxes as $mbox_name) {
         if ($search_request && isset($_SESSION['search'])
             && $_SESSION['search_request'] == $search_request
         ) {
-            $_SESSION['search'] = $RCMAIL->imap->refresh_search();
+            $_SESSION['search'] = $RCMAIL->storage->refresh_search();
         }
 
         if (!empty($_GET['_quota']))
@@ -68,28 +68,32 @@ foreach ($a_mailboxes as $mbox_name) {
         if (empty($_GET['_list']))
             continue;
 
-        // get overall message count; allow caching because rcube_imap::mailbox_status() did a refresh
-        $all_count = $RCMAIL->imap->messagecount(null, $RCMAIL->imap->threading ? 'THREADS' : 'ALL');
+        // get overall message count; allow caching because rcube_storage::folder_status() did a refresh
+        $all_count = $RCMAIL->storage->count(null, $RCMAIL->storage->get_threading() ? 'THREADS' : 'ALL');
+
+        $page      = $RCMAIL->storage->get_page();
+        $page_size = $RCMAIL->storage->get_pagesize();
 
         // check current page if we're not on the first page
-        if ($all_count && $RCMAIL->imap->list_page > 1) {
-            $remaining = $all_count - $RCMAIL->imap->page_size * ($RCMAIL->imap->list_page - 1);
+        if ($all_count && $page > 1) {
+            $remaining = $all_count - $page_size * ($page - 1);
             if ($remaining <= 0) {
-                $RCMAIL->imap->set_page($RCMAIL->imap->list_page-1);
-                $_SESSION['page'] = $RCMAIL->imap->list_page;
+                $page -= 1;
+                $RCMAIL->storage->set_page($page);
+                $_SESSION['page'] = $page;
             }
         }
 
         $OUTPUT->set_env('messagecount', $all_count);
-        $OUTPUT->set_env('pagecount', ceil($all_count/$RCMAIL->imap->page_size));
+        $OUTPUT->set_env('pagecount', ceil($all_count/$page_size));
         $OUTPUT->command('set_rowcount', rcmail_get_messagecount_text($all_count), $mbox_name);
-        $OUTPUT->set_env('current_page', $all_count ? $RCMAIL->imap->list_page : 1);
+        $OUTPUT->set_env('current_page', $all_count ? $page : 1);
 
         // remove old rows (and clear selection if new list is empty)
         $OUTPUT->command('message_list.clear', $all_count ? false : true);
 
         if ($all_count) {
-            $a_headers = $RCMAIL->imap->list_headers($mbox_name, null, $_SESSION['sort_col'], $_SESSION['sort_order']);
+            $a_headers = $RCMAIL->storage->list_messages($mbox_name, null, $_SESSION['sort_col'], $_SESSION['sort_order']);
             // add message rows
             rcmail_js_message_list($a_headers, false);
             // remove messages that don't exists from list selection array
diff --git a/program/steps/mail/compose.inc b/program/steps/mail/compose.inc
index 274983a18..687849863 100644
--- a/program/steps/mail/compose.inc
+++ b/program/steps/mail/compose.inc
@@ -56,7 +56,7 @@ if (!is_array($COMPOSE))
   $_SESSION['compose_data_'.$COMPOSE_ID] = array(
     'id'      => $COMPOSE_ID,
     'param'   => request2param(RCUBE_INPUT_GET),
-    'mailbox' => $RCMAIL->imap->get_mailbox_name(),
+    'mailbox' => $RCMAIL->storage->get_folder(),
   );
   $COMPOSE =& $_SESSION['compose_data_'.$COMPOSE_ID];
 
@@ -134,7 +134,7 @@ if (!empty($CONFIG['drafts_mbox'])) {
   $OUTPUT->set_env('draft_autosave', $CONFIG['draft_autosave']);
 }
 // set current mailbox in client environment
-$OUTPUT->set_env('mailbox', $RCMAIL->imap->get_mailbox_name());
+$OUTPUT->set_env('mailbox', $RCMAIL->storage->get_folder());
 $OUTPUT->set_env('sig_above', $RCMAIL->config->get('sig_above', false));
 $OUTPUT->set_env('top_posting', $RCMAIL->config->get('top_posting', false));
 $OUTPUT->set_env('recipients_separator', trim($RCMAIL->config->get('recipients_separator', ',')));
@@ -147,7 +147,7 @@ if ($font && !is_array($font)) {
 
 // get reference message and set compose mode
 if ($msg_uid = $COMPOSE['param']['draft_uid']) {
-  $RCMAIL->imap->set_mailbox($CONFIG['drafts_mbox']);
+  $RCMAIL->storage->set_folder($CONFIG['drafts_mbox']);
   $compose_mode = RCUBE_COMPOSE_DRAFT;
 }
 else if ($msg_uid = $COMPOSE['param']['reply_uid'])
@@ -179,10 +179,10 @@ if (!empty($msg_uid))
 
   // make sure message is marked as read
   if ($MESSAGE && $MESSAGE->headers && empty($MESSAGE->headers->flags['SEEN']))
-    $RCMAIL->imap->set_flag($msg_uid, 'SEEN');
+    $RCMAIL->storage->set_flag($msg_uid, 'SEEN');
 
   if (!empty($MESSAGE->headers->charset))
-    $RCMAIL->imap->set_charset($MESSAGE->headers->charset);
+    $RCMAIL->storage->set_charset($MESSAGE->headers->charset);
 
   if ($compose_mode == RCUBE_COMPOSE_REPLY)
   {
@@ -1051,12 +1051,12 @@ function rcmail_write_forward_attachment(&$message)
     $temp_dir = unslashify($RCMAIL->config->get('temp_dir'));
     $path = tempnam($temp_dir, 'rcmAttmnt');
     if ($fp = fopen($path, 'w')) {
-      $RCMAIL->imap->get_raw_body($message->uid, $fp);
+      $RCMAIL->storage->get_raw_body($message->uid, $fp);
       fclose($fp);
     } else
       return false;
   } else {
-    $data = $RCMAIL->imap->get_raw_body($message->uid);
+    $data = $RCMAIL->storage->get_raw_body($message->uid);
   }
 
   $attachment = array(
@@ -1428,16 +1428,16 @@ function rcmail_check_sent_folder($folder, $create=false)
 {
   global $RCMAIL;
 
-  if ($RCMAIL->imap->mailbox_exists($folder, true)) {
+  if ($RCMAIL->storage->folder_exists($folder, true)) {
     return true;
   }
 
   // folder may exist but isn't subscribed (#1485241)
   if ($create) {
-    if (!$RCMAIL->imap->mailbox_exists($folder))
-      return $RCMAIL->imap->create_mailbox($folder, true);
+    if (!$RCMAIL->storage->folder_exists($folder))
+      return $RCMAIL->storage->create_folder($folder, true);
     else
-      return $RCMAIL->imap->subscribe($folder);
+      return $RCMAIL->storage->subscribe($folder);
   }
 
   return false;
diff --git a/program/steps/mail/copy.inc b/program/steps/mail/copy.inc
index edb6af3d5..e553adc14 100644
--- a/program/steps/mail/copy.inc
+++ b/program/steps/mail/copy.inc
@@ -29,7 +29,7 @@ if (!empty($_POST['_uid']) && !empty($_POST['_target_mbox'])) {
     $target = get_input_value('_target_mbox', RCUBE_INPUT_POST, true);
     $mbox = get_input_value('_mbox', RCUBE_INPUT_POST, true);
 
-    $copied = $RCMAIL->imap->copy_message($uids, $target, $mbox);
+    $copied = $RCMAIL->storage->copy_message($uids, $target, $mbox);
 
     if (!$copied) {
         // send error message
diff --git a/program/steps/mail/folders.inc b/program/steps/mail/folders.inc
index 6e687b06a..2aa83ee0d 100644
--- a/program/steps/mail/folders.inc
+++ b/program/steps/mail/folders.inc
@@ -27,7 +27,7 @@ $mbox = get_input_value('_mbox', RCUBE_INPUT_POST, true);
 // send EXPUNGE command
 if ($RCMAIL->action == 'expunge') {
 
-    $success = $RCMAIL->imap->expunge($mbox);
+    $success = $RCMAIL->storage->expunge_folder($mbox);
 
     // reload message list if current mailbox
     if ($success) {
@@ -48,7 +48,7 @@ if ($RCMAIL->action == 'expunge') {
 // clear mailbox
 else if ($RCMAIL->action == 'purge')
 {
-    $delimiter = $RCMAIL->imap->get_hierarchy_delimiter();
+    $delimiter = $RCMAIL->storage->get_hierarchy_delimiter();
     $trash_regexp = '/^' . preg_quote($CONFIG['trash_mbox'] . $delimiter, '/') . '/';
     $junk_regexp  = '/^' . preg_quote($CONFIG['junk_mbox'] . $delimiter, '/') . '/';
 
@@ -56,7 +56,7 @@ else if ($RCMAIL->action == 'purge')
     if ($mbox == $CONFIG['trash_mbox'] || $mbox == $CONFIG['junk_mbox']
         || preg_match($trash_regexp, $mbox) || preg_match($junk_regexp, $mbox)
     ) {
-        $success = $RCMAIL->imap->clear_mailbox($mbox);
+        $success = $RCMAIL->storage->clear_folder($mbox);
 
         if ($success) {
             $OUTPUT->show_message('folderpurged', 'confirmation');
diff --git a/program/steps/mail/func.inc b/program/steps/mail/func.inc
index 5d0b30a0e..0ffffc5fc 100644
--- a/program/steps/mail/func.inc
+++ b/program/steps/mail/func.inc
@@ -28,31 +28,17 @@ $SEARCH_MODS_DEFAULT = array(
     $DRAFTS_MBOX => array('subject'=>1, 'to'=>1)
 );
 
-// actions that do not require imap connection here
-$NOIMAP_ACTIONS = array('addcontact', 'autocomplete', 'upload', 'display-attachment', 'remove-attachment', 'get');
-
-// always instantiate imap object (but not yet connect to server)
-$RCMAIL->imap_init();
-
-// log in to imap server
-if (!in_array($RCMAIL->action, $NOIMAP_ACTIONS) && !$RCMAIL->imap_connect()) {
-  $RCMAIL->kill_session();
-
-  if ($OUTPUT->ajax_call)
-    $OUTPUT->redirect(array(), 2000);
-
-  $OUTPUT->set_env('task', 'login');
-  $OUTPUT->send('login');
-}
+// always instantiate storage object (but not connect to server yet)
+$RCMAIL->storage_init();
 
 // set imap properties and session vars
 if (strlen(trim($mbox = get_input_value('_mbox', RCUBE_INPUT_GPC, true))))
-  $RCMAIL->imap->set_mailbox(($_SESSION['mbox'] = $mbox));
-else if ($RCMAIL->imap)
-  $_SESSION['mbox'] = $RCMAIL->imap->get_mailbox_name();
+  $RCMAIL->storage->set_folder(($_SESSION['mbox'] = $mbox));
+else if ($RCMAIL->storage)
+  $_SESSION['mbox'] = $RCMAIL->storage->get_folder();
 
 if (!empty($_GET['_page']))
-  $RCMAIL->imap->set_page(($_SESSION['page'] = intval($_GET['_page'])));
+  $RCMAIL->storage->set_page(($_SESSION['page'] = intval($_GET['_page'])));
 
 // set default sort col/order to session
 if (!isset($_SESSION['sort_col']))
@@ -69,28 +55,28 @@ if (isset($_GET['_threads'])) {
     unset($a_threading[$_SESSION['mbox']]);
   $RCMAIL->user->save_prefs(array('message_threading' => $a_threading));
 }
-$RCMAIL->imap->set_threading($a_threading[$_SESSION['mbox']]);
+$RCMAIL->storage->set_threading($a_threading[$_SESSION['mbox']]);
 
 // set message set for search result
 if (!empty($_REQUEST['_search']) && isset($_SESSION['search'])
     && $_SESSION['search_request'] == $_REQUEST['_search']
 ) {
-  $RCMAIL->imap->set_search_set($_SESSION['search']);
+  $RCMAIL->storage->set_search_set($_SESSION['search']);
   $OUTPUT->set_env('search_request', $_REQUEST['_search']);
   $OUTPUT->set_env('search_text', $_SESSION['last_text_search']);
 }
 
 // set main env variables, labels and page title
 if (empty($RCMAIL->action) || $RCMAIL->action == 'list') {
-  $mbox_name = $RCMAIL->imap->get_mailbox_name();
+  $mbox_name = $RCMAIL->storage->get_folder();
 
   if (empty($RCMAIL->action)) {
     // initialize searching result if search_filter is used
     if ($_SESSION['search_filter'] && $_SESSION['search_filter'] != 'ALL') {
       $search_request = md5($mbox_name.$_SESSION['search_filter']);
 
-      $RCMAIL->imap->search($mbox_name, $_SESSION['search_filter'], RCMAIL_CHARSET, $_SESSION['sort_col']);
-      $_SESSION['search'] = $RCMAIL->imap->get_search_set();
+      $RCMAIL->storage->search($mbox_name, $_SESSION['search_filter'], RCMAIL_CHARSET, $_SESSION['sort_col']);
+      $_SESSION['search'] = $RCMAIL->storage->get_search_set();
       $_SESSION['search_request'] = $search_request;
       $OUTPUT->set_env('search_request', $search_request);
     }
@@ -99,13 +85,15 @@ if (empty($RCMAIL->action) || $RCMAIL->action == 'list') {
       $OUTPUT->set_env('search_mods', $search_mods);
   }
 
+  $threading = (bool) $RCMAIL->storage->get_threading();
+
   // set current mailbox and some other vars in client environment
   $OUTPUT->set_env('mailbox', $mbox_name);
-  $OUTPUT->set_env('pagesize', $RCMAIL->imap->page_size);
-  $OUTPUT->set_env('quota', $RCMAIL->imap->get_capability('QUOTA'));
-  $OUTPUT->set_env('delimiter', $RCMAIL->imap->get_hierarchy_delimiter());
-  $OUTPUT->set_env('threading', (bool) $RCMAIL->imap->threading);
-  $OUTPUT->set_env('threads', $RCMAIL->imap->threading || $RCMAIL->imap->get_capability('THREAD'));
+  $OUTPUT->set_env('pagesize', $RCMAIL->storage->get_pagesize());
+  $OUTPUT->set_env('quota', $RCMAIL->storage->get_capability('QUOTA'));
+  $OUTPUT->set_env('delimiter', $RCMAIL->storage->get_hierarchy_delimiter());
+  $OUTPUT->set_env('threading', $threading);
+  $OUTPUT->set_env('threads', $threading || $RCMAIL->storage->get_capability('THREAD'));
   $OUTPUT->set_env('preview_pane_mark_read', $RCMAIL->config->get('preview_pane_mark_read', 0));
 
   if ($CONFIG['flag_for_deletion'])
@@ -130,7 +118,7 @@ if (empty($RCMAIL->action) || $RCMAIL->action == 'list') {
       'movingmessage', 'copyingmessage', 'deletingmessage', 'markingmessage',
       'copy', 'move', 'quota');
 
-  $OUTPUT->set_pagetitle(rcmail_localize_foldername($RCMAIL->imap->mod_mailbox($mbox_name)));
+  $OUTPUT->set_pagetitle(rcmail_localize_foldername($RCMAIL->storage->mod_folder($mbox_name)));
 }
 
 
@@ -161,8 +149,8 @@ function rcmail_message_list($attrib)
   // save some variables for use in ajax list
   $_SESSION['list_attrib'] = $attrib;
 
-  $mbox = $RCMAIL->imap->get_mailbox_name();
-  $delim = $RCMAIL->imap->get_hierarchy_delimiter();
+  $mbox = $RCMAIL->storage->get_folder();
+  $delim = $RCMAIL->storage->get_hierarchy_delimiter();
 
   // show 'to' instead of 'from' in sent/draft messages
   if ((strpos($mbox.$delim, $CONFIG['sent_mbox'].$delim)===0 || strpos($mbox.$delim, $CONFIG['drafts_mbox'].$delim)===0)
@@ -218,8 +206,8 @@ function rcmail_js_message_list($a_headers, $insert_top=FALSE, $a_show_cols=null
     $head_replace = true;
   }
 
-  $mbox = $RCMAIL->imap->get_mailbox_name();
-  $delim = $RCMAIL->imap->get_hierarchy_delimiter();
+  $mbox = $RCMAIL->storage->get_folder();
+  $delim = $RCMAIL->storage->get_hierarchy_delimiter();
 
   // make sure 'threads' and 'subject' columns are present
   if (!in_array('subject', $a_show_cols))
@@ -317,7 +305,7 @@ function rcmail_js_message_list($a_headers, $insert_top=FALSE, $a_show_cols=null
       $insert_top);
   }
 
-  if ($RCMAIL->imap->threading) {
+  if ($RCMAIL->storage->get_threading()) {
     $OUTPUT->command('init_threads', (array) $roots, $mbox);
   }
 }
@@ -430,22 +418,24 @@ function rcmail_get_messagecount_text($count=NULL, $page=NULL)
 {
   global $RCMAIL;
 
-  if ($page===NULL)
-    $page = $RCMAIL->imap->list_page;
+  if ($page === NULL) {
+    $page = $RCMAIL->storage->get_page();
+  }
 
-  $start_msg = ($page-1) * $RCMAIL->imap->page_size + 1;
+  $page_size = $RCMAIL->storage->get_pagesize();
+  $start_msg = ($page-1) * $page_size + 1;
 
   if ($count!==NULL)
     $max = $count;
   else if ($RCMAIL->action)
-    $max = $RCMAIL->imap->messagecount(NULL, $RCMAIL->imap->threading ? 'THREADS' : 'ALL');
+    $max = $RCMAIL->storage->count(NULL, $RCMAIL->storage->get_threading() ? 'THREADS' : 'ALL');
 
   if ($max==0)
     $out = rcube_label('mailboxempty');
   else
-    $out = rcube_label(array('name' => $RCMAIL->imap->threading ? 'threadsfromto' : 'messagesfromto',
+    $out = rcube_label(array('name' => $RCMAIL->storage->get_threading() ? 'threadsfromto' : 'messagesfromto',
             'vars' => array('from'  => $start_msg,
-            'to'    => min($max, $start_msg + $RCMAIL->imap->page_size - 1),
+            'to'    => min($max, $start_msg + $page_size - 1),
             'count' => $max)));
 
   return Q($out);
@@ -468,7 +458,7 @@ function rcmail_mailbox_name_display($attrib)
 function rcmail_get_mailbox_name_text()
 {
   global $RCMAIL;
-  return rcmail_localize_foldername($RCMAIL->imap->get_mailbox_name());
+  return rcmail_localize_foldername($RCMAIL->storage->get_folder());
 }
 
 
@@ -479,7 +469,7 @@ function rcmail_send_unread_count($mbox_name, $force=false, $count=null, $mark='
   $old_unseen = rcmail_get_unseen_count($mbox_name);
 
   if ($count === null)
-    $unseen = $RCMAIL->imap->messagecount($mbox_name, 'UNSEEN', $force);
+    $unseen = $RCMAIL->storage->count($mbox_name, 'UNSEEN', $force);
   else
     $unseen = $count;
 
@@ -590,7 +580,7 @@ function rcmail_wash_html($html, $p, $cid_replaces)
   // fix (unknown/malformed) HTML tags before "wash"
   $html = preg_replace_callback('/(<[\/]*)([^\s>]+)/', 'rcmail_html_tag_callback', $html);
 
-  // charset was converted to UTF-8 in rcube_imap::get_message_part(),
+  // charset was converted to UTF-8 in rcube_storage::get_message_part(),
   // change/add charset specification in HTML accordingly,
   // washtml cannot work without that
   $meta = '<meta http-equiv="Content-Type" content="text/html; charset='.RCMAIL_CHARSET.'" />';
@@ -1010,7 +1000,7 @@ function rcmail_message_body($attrib)
         if (!rcmail_mem_check($part->size * 10)) {
           $out .= html::span('part-notice', rcube_label('messagetoobig'). ' '
             . html::a('?_task=mail&_action=get&_download=1&_uid='.$MESSAGE->uid.'&_part='.$part->mime_id
-              .'&_mbox='. urlencode($RCMAIL->imap->get_mailbox_name()), rcube_label('download')));
+              .'&_mbox='. urlencode($RCMAIL->storage->get_folder()), rcube_label('download')));
           continue;
         }
 
@@ -1056,7 +1046,7 @@ function rcmail_message_body($attrib)
     if (!rcmail_mem_check(strlen($MESSAGE->body) * 10)) {
       $out .= html::span('part-notice', rcube_label('messagetoobig'). ' '
         . html::a('?_task=mail&_action=get&_download=1&_uid='.$MESSAGE->uid.'&_part=0'
-          .'&_mbox='. urlencode($RCMAIL->imap->get_mailbox_name()), rcube_label('download')));
+          .'&_mbox='. urlencode($RCMAIL->storage->get_folder()), rcube_label('download')));
     }
     else {
       $plugin = $RCMAIL->plugins->exec_hook('message_body_prefix', array(
@@ -1477,7 +1467,7 @@ function rcmail_send_mdn($message, &$smtp_error)
     $message = new rcube_message($message);
 
   if ($message->headers->mdn_to && empty($message->headers->flags['MDNSENT']) &&
-    ($RCMAIL->imap->check_permflag('MDNSENT') || $RCMAIL->imap->check_permflag('*')))
+    ($RCMAIL->storage->check_permflag('MDNSENT') || $RCMAIL->storage->check_permflag('*')))
   {
     $identity = $RCMAIL->user->get_identity();
     $sender = format_email_recipient($identity['email'], $identity['name']);
@@ -1533,7 +1523,7 @@ function rcmail_send_mdn($message, &$smtp_error)
 
     if ($sent)
     {
-      $RCMAIL->imap->set_flag($message->uid, 'MDNSENT');
+      $RCMAIL->storage->set_flag($message->uid, 'MDNSENT');
       return true;
     }
   }
@@ -1596,7 +1586,7 @@ function rcmail_message_error($uid=null)
 
   // Set env variables for messageerror.html template
   if ($RCMAIL->action == 'show') {
-    $mbox_name = $RCMAIL->imap->get_mailbox_name();
+    $mbox_name = $RCMAIL->storage->get_folder();
     $RCMAIL->output->set_env('mailbox', $mbox_name);
     $RCMAIL->output->set_env('uid', null);
   }
diff --git a/program/steps/mail/get.inc b/program/steps/mail/get.inc
index d114e7c61..7da8f13fa 100644
--- a/program/steps/mail/get.inc
+++ b/program/steps/mail/get.inc
@@ -36,7 +36,7 @@ if (!empty($_GET['_preload'])) {
 ob_end_clean();
 
 // Now we need IMAP connection
-if (!$RCMAIL->imap_connect()) {
+if (!$RCMAIL->storage_connect()) {
   // Get action is often executed simultanously.
   // Some servers have MAXPERIP or other limits.
   // To workaround this we'll wait for some time
@@ -117,7 +117,7 @@ else if (strlen($pid = get_input_value('_part', RCUBE_INPUT_GET))) {
       if (!rcmail_mem_check($part->size * 10)) {
         $out = '<body>' . rcube_label('messagetoobig'). ' '
           . html::a('?_task=mail&_action=get&_download=1&_uid='.$MESSAGE->uid.'&_part='.$part->mime_id
-            .'&_mbox='. urlencode($RCMAIL->imap->get_mailbox_name()), rcube_label('download')) . '</body></html>';
+            .'&_mbox='. urlencode($RCMAIL->storage->get_folder()), rcube_label('download')) . '</body></html>';
       }
       else {
         // get part body if not available
@@ -157,7 +157,7 @@ else if (strlen($pid = get_input_value('_part', RCUBE_INPUT_GET))) {
           $stdout = fopen('php://output', 'w');
           stream_filter_register('rcube_content', 'rcube_content_filter') or die('Failed to register content filter');
           stream_filter_append($stdout, 'rcube_content');
-          $RCMAIL->imap->get_message_part($MESSAGE->uid, $part->mime_id, $part, false, $stdout);
+          $RCMAIL->storage->get_message_part($MESSAGE->uid, $part->mime_id, $part, false, $stdout);
         }
       }
       else {
@@ -165,7 +165,7 @@ else if (strlen($pid = get_input_value('_part', RCUBE_INPUT_GET))) {
         if ($part->body)
           echo $part->body;
         else if ($part->size)
-          $RCMAIL->imap->get_message_part($MESSAGE->uid, $part->mime_id, $part, true);
+          $RCMAIL->storage->get_message_part($MESSAGE->uid, $part->mime_id, $part, true);
       }
     }
 
diff --git a/program/steps/mail/getunread.inc b/program/steps/mail/getunread.inc
index 39880b99b..64e7a6aee 100644
--- a/program/steps/mail/getunread.inc
+++ b/program/steps/mail/getunread.inc
@@ -19,11 +19,11 @@
 
 */
 
-$a_folders = $RCMAIL->imap->list_mailboxes('', '*', 'mail');
+$a_folders = $RCMAIL->storage->list_folders_subscribed('', '*', 'mail');
 
 if (!empty($a_folders))
 {
-  $current = $RCMAIL->imap->get_mailbox_name();
+  $current = $RCMAIL->storage->get_folder();
   $inbox = ($current == 'INBOX');
   $check_all = (bool)$RCMAIL->config->get('check_all_folders');
 
@@ -33,7 +33,7 @@ if (!empty($a_folders))
     if (!$check_all && $unseen_old !== null && $mbox_row != $current)
       $unseen = $unseen_old;
     else
-      $unseen = $RCMAIL->imap->messagecount($mbox_row, 'UNSEEN', $unseen_old === null);
+      $unseen = $RCMAIL->storage->count($mbox_row, 'UNSEEN', $unseen_old === null);
 
     if ($unseen || $unseen_old === null) {
       $OUTPUT->command('set_unread_count', $mbox_row, $unseen, $inbox && $mbox_row == 'INBOX');
diff --git a/program/steps/mail/headers.inc b/program/steps/mail/headers.inc
index 5eee4bdef..0cce5a503 100644
--- a/program/steps/mail/headers.inc
+++ b/program/steps/mail/headers.inc
@@ -20,7 +20,7 @@
 
 if ($uid = get_input_value('_uid', RCUBE_INPUT_POST))
 {
-    $source = $RCMAIL->imap->get_raw_headers($uid);
+    $source = $RCMAIL->storage->get_raw_headers($uid);
 
     if ($source !== false) {
         $source = htmlspecialchars(trim($source));
diff --git a/program/steps/mail/list.inc b/program/steps/mail/list.inc
index c2a47488f..8bfb4c8f1 100644
--- a/program/steps/mail/list.inc
+++ b/program/steps/mail/list.inc
@@ -51,30 +51,31 @@ if ($cols = get_input_value('_cols', RCUBE_INPUT_GET))
 if ($save_arr)
   $RCMAIL->user->save_prefs($save_arr);
 
-$mbox_name = $RCMAIL->imap->get_mailbox_name();
+$mbox_name = $RCMAIL->storage->get_folder();
+$threading = (bool) $RCMAIL->storage->get_threading();
 
 // Synchronize mailbox cache, handle flag changes
-$RCMAIL->imap->mailbox_sync($mbox_name);
+$RCMAIL->storage->folder_sync($mbox_name);
 
 // initialize searching result if search_filter is used
 if ($_SESSION['search_filter'] && $_SESSION['search_filter'] != 'ALL')
 {
   $search_request = md5($mbox_name.$_SESSION['search_filter']);
-  $RCMAIL->imap->search($mbox_name, $_SESSION['search_filter'], RCMAIL_CHARSET, $sort_col);
-  $_SESSION['search'] = $RCMAIL->imap->get_search_set();
+  $RCMAIL->storage->search($mbox_name, $_SESSION['search_filter'], RCMAIL_CHARSET, $sort_col);
+  $_SESSION['search'] = $RCMAIL->storage->get_search_set();
   $_SESSION['search_request'] = $search_request;
   $OUTPUT->set_env('search_request', $search_request);
 }
 
 // fetch message headers
-if ($count = $RCMAIL->imap->messagecount($mbox_name, $RCMAIL->imap->threading ? 'THREADS' : 'ALL', !empty($_REQUEST['_refresh'])))
-  $a_headers = $RCMAIL->imap->list_headers($mbox_name, NULL, $sort_col, $sort_order);
+if ($count = $RCMAIL->storage->count($mbox_name, $threading ? 'THREADS' : 'ALL', !empty($_REQUEST['_refresh'])))
+  $a_headers = $RCMAIL->storage->list_messages($mbox_name, NULL, $sort_col, $sort_order);
 
 // update search set (possible change of threading mode)
 if (!empty($_REQUEST['_search']) && isset($_SESSION['search'])
     && $_SESSION['search_request'] == $_REQUEST['_search']
 ) {
-  $_SESSION['search'] = $RCMAIL->imap->get_search_set();
+  $_SESSION['search'] = $RCMAIL->storage->get_search_set();
 }
 // remove old search data
 else if (empty($_REQUEST['_search']) && isset($_SESSION['search'])) {
@@ -91,11 +92,11 @@ if (empty($search_request) && empty($a_headers)) {
 rcmail_send_unread_count($mbox_name, !empty($_REQUEST['_refresh']), $unseen);
 
 // update message count display
-$pages = ceil($count/$RCMAIL->imap->page_size);
+$pages = ceil($count/$RCMAIL->storage->get_pagesize());
 $OUTPUT->set_env('messagecount', $count);
 $OUTPUT->set_env('pagecount', $pages);
-$OUTPUT->set_env('threading', (bool) $RCMAIL->imap->threading);
-$OUTPUT->set_env('current_page', $count ? $RCMAIL->imap->list_page : 1);
+$OUTPUT->set_env('threading', $threading);
+$OUTPUT->set_env('current_page', $count ? $RCMAIL->storage->get_page() : 1);
 $OUTPUT->command('set_rowcount', rcmail_get_messagecount_text($count), $mbox_name);
 $OUTPUT->command('set_mailboxname', rcmail_get_mailbox_name_text());
 
@@ -108,7 +109,7 @@ if (isset($a_headers) && count($a_headers))
 }
 else {
   // handle IMAP errors (e.g. #1486905)
-  if ($err_code = $RCMAIL->imap->get_error_code()) {
+  if ($err_code = $RCMAIL->storage->get_error_code()) {
     rcmail_display_server_error();
   }
   else if ($search_request)
diff --git a/program/steps/mail/mark.inc b/program/steps/mail/mark.inc
index 3b52dfe4f..ab64debb7 100644
--- a/program/steps/mail/mark.inc
+++ b/program/steps/mail/mark.inc
@@ -30,18 +30,20 @@ $a_flags_map = array(
   'flagged' => 'FLAGGED',
   'unflagged' => 'UNFLAGGED');
 
+$threading = (bool) $RCMAIL->storage->get_threading();
+
 if (($uids = get_input_value('_uid', RCUBE_INPUT_POST)) && ($flag = get_input_value('_flag', RCUBE_INPUT_POST)))
 {
   $flag = $a_flags_map[$flag] ? $a_flags_map[$flag] : strtoupper($flag);
 
   if ($flag == 'DELETED' && $CONFIG['skip_deleted'] && $_POST['_from'] != 'show') {
     // count messages before changing anything
-    $old_count = $RCMAIL->imap->messagecount(NULL, $RCMAIL->imap->threading ? 'THREADS' : 'ALL');
-    $old_pages = ceil($old_count / $RCMAIL->imap->page_size);
+    $old_count = $RCMAIL->storage->count(NULL, $threading ? 'THREADS' : 'ALL');
+    $old_pages = ceil($old_count / $RCMAIL->storage->get_pagesize());
     $count = sizeof(explode(',', $uids));
   }
 
-  $marked = $RCMAIL->imap->set_flag($uids, $flag);
+  $marked = $RCMAIL->storage->set_flag($uids, $flag);
 
   if (!$marked) {
     // send error message
@@ -57,14 +59,14 @@ if (($uids = get_input_value('_uid', RCUBE_INPUT_POST)) && ($flag = get_input_va
 
   if ($flag == 'DELETED' && $CONFIG['read_when_deleted'] && !empty($_POST['_ruid'])) {
     $ruids = get_input_value('_ruid', RCUBE_INPUT_POST);
-    $read = $RCMAIL->imap->set_flag($ruids, 'SEEN');
+    $read = $RCMAIL->storage->set_flag($ruids, 'SEEN');
 
     if ($read && !$CONFIG['skip_deleted'])
       $OUTPUT->command('flag_deleted_as_read', $ruids);
   }
 
   if ($flag == 'SEEN' || $flag == 'UNSEEN' || ($flag == 'DELETED' && !$CONFIG['skip_deleted'])) {
-    rcmail_send_unread_count($RCMAIL->imap->get_mailbox_name());
+    rcmail_send_unread_count($RCMAIL->storage->get_folder());
   }
   else if ($flag == 'DELETED' && $CONFIG['skip_deleted']) {
     if ($_POST['_from'] == 'show') {
@@ -73,31 +75,35 @@ if (($uids = get_input_value('_uid', RCUBE_INPUT_POST)) && ($flag = get_input_va
       else
         $OUTPUT->command('command', 'list');
     } else {
+      $search_request = get_input_value('_search', RCUBE_INPUT_GPC);
       // refresh saved search set after moving some messages
-      if (($search_request = get_input_value('_search', RCUBE_INPUT_GPC)) && $RCMAIL->imap->search_set) {
-        $_SESSION['search'] = $RCMAIL->imap->refresh_search();
+      if ($search_request && $RCMAIL->storage->get_search_set()) {
+        $_SESSION['search'] = $RCMAIL->storage->refresh_search();
       }
 
-      $msg_count      = $RCMAIL->imap->messagecount(NULL, $RCMAIL->imap->threading ? 'THREADS' : 'ALL');
-      $pages          = ceil($msg_count / $RCMAIL->imap->page_size);
-      $nextpage_count = $old_count - $RCMAIL->imap->page_size * $RCMAIL->imap->list_page;
-      $remaining      = $msg_count - $RCMAIL->imap->page_size * ($RCMAIL->imap->list_page - 1);
+      $msg_count      = $RCMAIL->storage->count(NULL, $threading ? 'THREADS' : 'ALL');
+      $page_size      = $RCMAIL->storage->get_pagesize();
+      $page           = $RCMAIL->storage->get_page();
+      $pages          = ceil($msg_count / $page_size);
+      $nextpage_count = $old_count - $page_size * $page;
+      $remaining      = $msg_count - $page_size * ($page - 1);
 
       // jump back one page (user removed the whole last page)
-      if ($RCMAIL->imap->list_page > 1 && $remaining == 0) {
-        $RCMAIL->imap->set_page($RCMAIL->imap->list_page-1);
-        $_SESSION['page'] = $RCMAIL->imap->list_page;
+      if ($page > 1 && $remaining == 0) {
+        $page -= 1;
+        $RCMAIL->storage->set_page($page);
+        $_SESSION['page'] = $page;
         $jump_back = true;
       }
 
       // update message count display
       $OUTPUT->set_env('messagecount', $msg_count);
-      $OUTPUT->set_env('current_page', $RCMAIL->imap->list_page);
+      $OUTPUT->set_env('current_page', $page);
       $OUTPUT->set_env('pagecount', $pages);
 
       // update mailboxlist
-      $mbox = $RCMAIL->imap->get_mailbox_name();
-      $unseen_count = $msg_count ? $RCMAIL->imap->messagecount($mbox, 'UNSEEN') : 0;
+      $mbox = $RCMAIL->storage->get_folder();
+      $unseen_count = $msg_count ? $RCMAIL->storage->count($mbox, 'UNSEEN') : 0;
       $old_unseen = rcmail_get_unseen_count($mbox);
 
       if ($old_unseen != $unseen_count) {
@@ -106,15 +112,16 @@ if (($uids = get_input_value('_uid', RCUBE_INPUT_POST)) && ($flag = get_input_va
       }
       $OUTPUT->command('set_rowcount', rcmail_get_messagecount_text($msg_count), $mbox);
 
-      if ($RCMAIL->imap->threading)
+      if ($threading) {
 	    $count = get_input_value('_count', RCUBE_INPUT_POST);
+      }
 
       // add new rows from next page (if any)
       if ($count && $uids != '*' && ($jump_back || $nextpage_count > 0)) {
         $sort_col   = isset($_SESSION['sort_col'])   ? $_SESSION['sort_col']   : $CONFIG['message_sort_col'];
         $sort_order = isset($_SESSION['sort_order']) ? $_SESSION['sort_order'] : $CONFIG['message_sort_order'];
 
-        $a_headers = $RCMAIL->imap->list_headers($mbox, NULL, $sort_col, $sort_order,
+        $a_headers = $RCMAIL->storage->list_messages($mbox, NULL, $sort_col, $sort_order,
 	    $jump_back ? NULL : $count);
 
         rcmail_js_message_list($a_headers, false);
diff --git a/program/steps/mail/move_del.inc b/program/steps/mail/move_del.inc
index 95a456ed5..63f27440f 100644
--- a/program/steps/mail/move_del.inc
+++ b/program/steps/mail/move_del.inc
@@ -24,8 +24,9 @@ if (!$OUTPUT->ajax_call)
   return;
 
 // count messages before changing anything
-$old_count = $RCMAIL->imap->messagecount(NULL, $RCMAIL->imap->threading ? 'THREADS' : 'ALL');
-$old_pages = ceil($old_count / $RCMAIL->imap->page_size);
+$threading = (bool) $RCMAIL->storage->get_threading();
+$old_count = $RCMAIL->storage->count(NULL, $threading ? 'THREADS' : 'ALL');
+$old_pages = ceil($old_count / $RCMAIL->storage->get_pagesize());
 
 // move messages
 if ($RCMAIL->action=='moveto' && !empty($_POST['_uid']) && strlen($_POST['_target_mbox'])) {
@@ -33,7 +34,7 @@ if ($RCMAIL->action=='moveto' && !empty($_POST['_uid']) && strlen($_POST['_targe
     $target = get_input_value('_target_mbox', RCUBE_INPUT_POST, true);
     $mbox = get_input_value('_mbox', RCUBE_INPUT_POST, true);
 
-    $moved = $RCMAIL->imap->move_message($uids, $target, $mbox);
+    $moved = $RCMAIL->storage->move_message($uids, $target, $mbox);
 
     if (!$moved) {
         // send error message
@@ -54,7 +55,7 @@ else if ($RCMAIL->action=='delete' && !empty($_POST['_uid'])) {
     $count = sizeof(explode(',', ($uids = get_input_value('_uid', RCUBE_INPUT_POST))));
     $mbox = get_input_value('_mbox', RCUBE_INPUT_POST, true);
 
-    $del = $RCMAIL->imap->delete_message($uids, $mbox);
+    $del = $RCMAIL->storage->delete_message($uids, $mbox);
 
     if (!$del) {
         // send error message
@@ -75,9 +76,11 @@ else {
     exit;
 }
 
+$search_request = get_input_value('_search', RCUBE_INPUT_GPC);
+
 // refresh saved search set after moving some messages
-if (($search_request = get_input_value('_search', RCUBE_INPUT_GPC)) && $RCMAIL->imap->search_set) {
-    $_SESSION['search'] = $RCMAIL->imap->refresh_search();
+if ($search_request && $RCMAIL->storage->get_search_set()) {
+    $_SESSION['search'] = $RCMAIL->storage->refresh_search();
 }
 
 if ($_POST['_from'] == 'show')
@@ -89,26 +92,29 @@ if ($_POST['_from'] == 'show')
 }
 else
 {
-  $msg_count      = $RCMAIL->imap->messagecount(NULL, $RCMAIL->imap->threading ? 'THREADS' : 'ALL');
-  $pages          = ceil($msg_count / $RCMAIL->imap->page_size);
-  $nextpage_count = $old_count - $RCMAIL->imap->page_size * $RCMAIL->imap->list_page;
-  $remaining      = $msg_count - $RCMAIL->imap->page_size * ($RCMAIL->imap->list_page - 1);
+  $msg_count      = $RCMAIL->storage->count(NULL, $threading ? 'THREADS' : 'ALL');
+  $page_size      = $RCMAIL->storage->get_pagesize();
+  $page           = $RCMAIL->storage->get_page();
+  $pages          = ceil($msg_count / $page_size);
+  $nextpage_count = $old_count - $page_size * $page;
+  $remaining      = $msg_count - $page_size * ($page - 1);
 
   // jump back one page (user removed the whole last page)
-  if ($RCMAIL->imap->list_page > 1 && $remaining == 0) {
-    $RCMAIL->imap->set_page($RCMAIL->imap->list_page-1);
-    $_SESSION['page'] = $RCMAIL->imap->list_page;
+  if ($page > 1 && $remaining == 0) {
+    $page -= 1;
+    $RCMAIL->storage->set_page($page);
+    $_SESSION['page'] = $page;
     $jump_back = true;
   }
 
   // update message count display
   $OUTPUT->set_env('messagecount', $msg_count);
-  $OUTPUT->set_env('current_page', $RCMAIL->imap->list_page);
+  $OUTPUT->set_env('current_page', $page);
   $OUTPUT->set_env('pagecount', $pages);
 
   // update mailboxlist
-  $mbox = $RCMAIL->imap->get_mailbox_name();
-  $unseen_count = $msg_count ? $RCMAIL->imap->messagecount($mbox, 'UNSEEN') : 0;
+  $mbox = $RCMAIL->storage->get_folder();
+  $unseen_count = $msg_count ? $RCMAIL->storage->count($mbox, 'UNSEEN') : 0;
   $old_unseen = rcmail_get_unseen_count($mbox);
 
   if ($old_unseen != $unseen_count) {
@@ -123,15 +129,16 @@ else
   $OUTPUT->command('set_quota', rcmail_quota_content());
   $OUTPUT->command('set_rowcount', rcmail_get_messagecount_text($msg_count), $mbox);
 
-  if ($RCMAIL->imap->threading)
+  if ($threading) {
     $count = get_input_value('_count', RCUBE_INPUT_POST);
+  }
 
   // add new rows from next page (if any)
   if ($addrows && $count && $uids != '*' && ($jump_back || $nextpage_count > 0)) {
     $sort_col   = isset($_SESSION['sort_col'])   ? $_SESSION['sort_col']   : $CONFIG['message_sort_col'];
     $sort_order = isset($_SESSION['sort_order']) ? $_SESSION['sort_order'] : $CONFIG['message_sort_order'];
 
-    $a_headers = $RCMAIL->imap->list_headers($mbox, NULL, $sort_col, $sort_order,
+    $a_headers = $RCMAIL->storage->list_messages($mbox, NULL, $sort_col, $sort_order,
       $jump_back ? NULL : $count);
 
     rcmail_js_message_list($a_headers, false);
diff --git a/program/steps/mail/pagenav.inc b/program/steps/mail/pagenav.inc
index f15ac38de..e74298b88 100644
--- a/program/steps/mail/pagenav.inc
+++ b/program/steps/mail/pagenav.inc
@@ -20,14 +20,14 @@
 */
 
 $uid   = get_input_value('_uid', RCUBE_INPUT_GET);
-$index = $RCMAIL->imap->message_index(null, $_SESSION['sort_col'], $_SESSION['sort_order']);
-$cnt   = $index->countMessages();
+$index = $RCMAIL->storage->index(null, $_SESSION['sort_col'], $_SESSION['sort_order']);
+$cnt   = $index->count_messages();
 
 if ($cnt && ($pos = $index->exists($uid, true)) !== false) {
-    $prev  = $pos ? $index->getElement($pos-1) : 0;
-    $first = $pos ? $index->getElement('FIRST') : 0;
-    $next  = $pos < $cnt-1 ? $index->getElement($pos+1) : 0;
-    $last  = $pos < $cnt-1 ? $index->getElement('LAST') : 0;
+    $prev  = $pos ? $index->get_element($pos-1) : 0;
+    $first = $pos ? $index->get_element('FIRST') : 0;
+    $next  = $pos < $cnt-1 ? $index->get_element($pos+1) : 0;
+    $last  = $pos < $cnt-1 ? $index->get_element('LAST') : 0;
 }
 
 // Set UIDs and activate navigation buttons
diff --git a/program/steps/mail/search.inc b/program/steps/mail/search.inc
index 42bdf9776..8835730e4 100644
--- a/program/steps/mail/search.inc
+++ b/program/steps/mail/search.inc
@@ -18,8 +18,8 @@
 $REMOTE_REQUEST = TRUE;
 
 // reset list_page and old search results
-$RCMAIL->imap->set_page(1);
-$RCMAIL->imap->set_search_set(NULL);
+$RCMAIL->storage->set_page(1);
+$RCMAIL->storage->set_search_set(NULL);
 $_SESSION['page'] = 1;
 
 // using encodeURI with javascript "should" give us
@@ -107,32 +107,32 @@ $search_str = trim($search_str);
 
 // execute IMAP search
 if ($search_str)
-  $RCMAIL->imap->search($mbox, $search_str, $imap_charset, $_SESSION['sort_col']);
+  $RCMAIL->storage->search($mbox, $search_str, $imap_charset, $_SESSION['sort_col']);
 
 // save search results in session
 if (!is_array($_SESSION['search']))
   $_SESSION['search'] = array();
 
 if ($search_str) {
-  $_SESSION['search'] = $RCMAIL->imap->get_search_set();
+  $_SESSION['search'] = $RCMAIL->storage->get_search_set();
   $_SESSION['last_text_search'] = $str;
 }
 $_SESSION['search_request'] = $search_request;
 
 
 // Get the headers
-$result_h = $RCMAIL->imap->list_headers($mbox, 1, $_SESSION['sort_col'], $_SESSION['sort_order']);
-$count = $RCMAIL->imap->messagecount($mbox, $RCMAIL->imap->threading ? 'THREADS' : 'ALL');
+$result_h = $RCMAIL->storage->list_messages($mbox, 1, $_SESSION['sort_col'], $_SESSION['sort_order']);
+$count = $RCMAIL->storage->count($mbox, $RCMAIL->storage->get_threading() ? 'THREADS' : 'ALL');
 
 
 // Make sure we got the headers
 if (!empty($result_h)) {
   rcmail_js_message_list($result_h);
   if ($search_str)
-    $OUTPUT->show_message('searchsuccessful', 'confirmation', array('nr' => $RCMAIL->imap->messagecount(NULL, 'ALL')));
+    $OUTPUT->show_message('searchsuccessful', 'confirmation', array('nr' => $RCMAIL->storage->count(NULL, 'ALL')));
 }
 // handle IMAP errors (e.g. #1486905)
-else  if ($err_code = $RCMAIL->imap->get_error_code()) {
+else  if ($err_code = $RCMAIL->storage->get_error_code()) {
   rcmail_display_server_error();
 }
 else {
@@ -142,8 +142,6 @@ else {
 // update message count display
 $OUTPUT->set_env('search_request', $search_str ? $search_request : '');
 $OUTPUT->set_env('messagecount', $count);
-$OUTPUT->set_env('pagecount', ceil($count/$RCMAIL->imap->page_size));
+$OUTPUT->set_env('pagecount', ceil($count/$RCMAIL->storage->get_pagesize()));
 $OUTPUT->command('set_rowcount', rcmail_get_messagecount_text($count, 1), $mbox);
 $OUTPUT->send();
-
-
diff --git a/program/steps/mail/sendmail.inc b/program/steps/mail/sendmail.inc
index 953c7521a..ea673fdcf 100644
--- a/program/steps/mail/sendmail.inc
+++ b/program/steps/mail/sendmail.inc
@@ -634,9 +634,9 @@ if (!$savedraft)
 
   // set replied/forwarded flag
   if ($COMPOSE['reply_uid'])
-    $RCMAIL->imap->set_flag($COMPOSE['reply_uid'], 'ANSWERED', $COMPOSE['mailbox']);
+    $RCMAIL->storage->set_flag($COMPOSE['reply_uid'], 'ANSWERED', $COMPOSE['mailbox']);
   else if ($COMPOSE['forward_uid'])
-    $RCMAIL->imap->set_flag($COMPOSE['forward_uid'], 'FORWARDED', $COMPOSE['mailbox']);
+    $RCMAIL->storage->set_flag($COMPOSE['forward_uid'], 'FORWARDED', $COMPOSE['mailbox']);
 
 } // End of SMTP Delivery Block
 
@@ -649,12 +649,12 @@ else
 
 if ($store_target) {
   // check if folder is subscribed
-  if ($RCMAIL->imap->mailbox_exists($store_target, true))
+  if ($RCMAIL->storage->folder_exists($store_target, true))
     $store_folder = true;
   // folder may be existing but not subscribed (#1485241)
-  else if (!$RCMAIL->imap->mailbox_exists($store_target))
-    $store_folder = $RCMAIL->imap->create_mailbox($store_target, true);
-  else if ($RCMAIL->imap->subscribe($store_target))
+  else if (!$RCMAIL->storage->folder_exists($store_target))
+    $store_folder = $RCMAIL->storage->create_folder($store_target, true);
+  else if ($RCMAIL->storage->subscribe($store_target))
     $store_folder = true;
 
   // append message to sent box
@@ -684,7 +684,7 @@ if ($store_target) {
             'message' => "Could not create message: ".$msg->getMessage()),
             TRUE, FALSE);
     else {
-      $saved = $RCMAIL->imap->save_message($store_target, $msg, $headers, $mailbody_file ? true : false);
+      $saved = $RCMAIL->storage->save_message($store_target, $msg, $headers, $mailbody_file ? true : false);
     }
 
     if ($mailbody_file) {
@@ -708,11 +708,11 @@ if ($store_target) {
   if ($olddraftmessageid) {
     // delete previous saved draft
     // @TODO: use message UID (remember to check UIDVALIDITY) to skip this SEARCH
-    $delete_idx = $RCMAIL->imap->search_once($CONFIG['drafts_mbox'],
+    $delete_idx = $RCMAIL->storage->search_once($CONFIG['drafts_mbox'],
         'HEADER Message-ID '.$olddraftmessageid);
 
     if ($del_uid = $delete_idx->getElement('FIRST')) {
-      $deleted = $RCMAIL->imap->delete_message($del_uid, $CONFIG['drafts_mbox']);
+      $deleted = $RCMAIL->storage->delete_message($del_uid, $CONFIG['drafts_mbox']);
 
       // raise error if deletion of old draft failed
       if (!$deleted)
@@ -733,7 +733,7 @@ if ($savedraft) {
 
   // remember new draft-uid ($saved could be an UID or TRUE here)
   if (is_bool($saved)) {
-    $draft_idx = $RCMAIL->imap->search_once($CONFIG['drafts_mbox'], 'HEADER Message-ID '.$msgid);
+    $draft_idx = $RCMAIL->storage->search_once($CONFIG['drafts_mbox'], 'HEADER Message-ID '.$msgid);
     $saved     = $draft_idx->getElement('FIRST');
   }
   $COMPOSE['param']['draft_uid'] = $saved;
diff --git a/program/steps/mail/show.inc b/program/steps/mail/show.inc
index aee563d52..7a3d3cd7f 100644
--- a/program/steps/mail/show.inc
+++ b/program/steps/mail/show.inc
@@ -30,14 +30,14 @@ if ($uid = get_input_value('_uid', RCUBE_INPUT_GET)) {
     rcmail_message_error($uid);
   }
 
-  $mbox_name = $RCMAIL->imap->get_mailbox_name();
+  $mbox_name = $RCMAIL->storage->get_folder();
 
   // show images?
   rcmail_check_safe($MESSAGE);
 
   // set message charset as default
   if (!empty($MESSAGE->headers->charset))
-    $RCMAIL->imap->set_charset($MESSAGE->headers->charset);
+    $RCMAIL->storage->set_charset($MESSAGE->headers->charset);
 
   $OUTPUT->set_pagetitle(abbreviate_string($MESSAGE->subject, 128, '...', true));
 
@@ -47,7 +47,7 @@ if ($uid = get_input_value('_uid', RCUBE_INPUT_GET)) {
   $OUTPUT->set_env('safemode', $MESSAGE->is_safe);
   $OUTPUT->set_env('sender', $MESSAGE->sender['string']);
   $OUTPUT->set_env('permaurl', rcmail_url('show', array('_uid' => $MESSAGE->uid, '_mbox' => $mbox_name)));
-  $OUTPUT->set_env('delimiter', $RCMAIL->imap->get_hierarchy_delimiter());
+  $OUTPUT->set_env('delimiter', $RCMAIL->storage->get_hierarchy_delimiter());
   $OUTPUT->set_env('mailbox', $mbox_name);
 
   // mimetypes supported by the browser (default settings)
@@ -77,7 +77,7 @@ if ($uid = get_input_value('_uid', RCUBE_INPUT_GET)) {
   if ($MESSAGE->headers->mdn_to
       && empty($MESSAGE->headers->flags['MDNSENT'])
       && empty($MESSAGE->headers->flags['SEEN'])
-      && ($RCMAIL->imap->check_permflag('MDNSENT') || $RCMAIL->imap->check_permflag('*'))
+      && ($RCMAIL->storage->check_permflag('MDNSENT') || $RCMAIL->storage->check_permflag('*'))
       && $mbox_name != $CONFIG['drafts_mbox']
       && $mbox_name != $CONFIG['sent_mbox']
   ) {
@@ -175,8 +175,8 @@ function rcmail_message_buttons()
 {
   global $MESSAGE, $RCMAIL, $CONFIG;
 
-  $mbox  = $RCMAIL->imap->get_mailbox_name();
-  $delim = $RCMAIL->imap->get_hierarchy_delimiter();
+  $mbox  = $RCMAIL->storage->get_folder();
+  $delim = $RCMAIL->storage->get_hierarchy_delimiter();
   $dbox  = $CONFIG['drafts_mbox'];
 
   // the message is not a draft
@@ -248,7 +248,7 @@ else
 if ($MESSAGE && $MESSAGE->headers && empty($MESSAGE->headers->flags['SEEN']) &&
   ($RCMAIL->action == 'show' || ($RCMAIL->action == 'preview' && intval($CONFIG['preview_pane_mark_read']) == 0)))
 {
-  if ($RCMAIL->imap->set_flag($MESSAGE->uid, 'SEEN')) {
+  if ($RCMAIL->storage->set_flag($MESSAGE->uid, 'SEEN')) {
     if ($count = rcmail_get_unseen_count($mbox_name)) {
       rcmail_set_unseen_count($mbox_name, $count - 1);
     }
diff --git a/program/steps/mail/viewsource.inc b/program/steps/mail/viewsource.inc
index e2b4e1b61..c9aeac4c1 100644
--- a/program/steps/mail/viewsource.inc
+++ b/program/steps/mail/viewsource.inc
@@ -24,7 +24,7 @@ ob_end_clean();
 // similar code as in program/steps/mail/get.inc
 if ($uid = get_input_value('_uid', RCUBE_INPUT_GET))
 {
-  $headers = $RCMAIL->imap->get_headers($uid);
+  $headers = $RCMAIL->storage->get_message_headers($uid);
   $charset = $headers->charset ? $headers->charset : $CONFIG['default_charset'];
   header("Content-Type: text/plain; charset={$charset}");
 
@@ -44,7 +44,7 @@ if ($uid = get_input_value('_uid', RCUBE_INPUT_GET))
     header("Content-Disposition: attachment; filename=\"$filename\"");
   }
 
-  $RCMAIL->imap->print_raw_body($uid);
+  $RCMAIL->storage->print_raw_body($uid);
 }
 else
 {