Few fixes.

modoboa/core/static/core/js/settings.js

@@ -40,6 +40,7 @@ Settings.prototype = {
      * Navigation callback: extensions.
      */
     extensions_callback: function(data) {
+        this.select_left_menu();        
         if (data.content) {
             $('#' + this.options.divid).html(data.content);
         }

modoboa/extensions/webmail/lib/imaputils.py

@@ -297,6 +297,7 @@ class IMAPconnector(object):
             self.capabilities = data[0].split()
 
     def logout(self):
+        """Logout from server."""
         try:
             self._cmd("CHECK")
         except ImapError:
@@ -304,7 +305,8 @@ class IMAPconnector(object):
         self._cmd("LOGOUT")
         del self.m
         self.m = None
-        del self.current_mailbox
+        if hasattr(self, "current_mailbox"):
+            del self.current_mailbox
 
     def parse_search_parameters(self, criterion, pattern):
         """Parse search information and apply them."""