Roshan, regarding following error
http://www.oxwall.org/ow_userfiles/plugins/base/1434-mailboxeroor.JPG . You will need to download MailBox plugin once more from the store (we did some changes and updated it a couple of minutes ago). Then via FTP or File Manager, delete previous folder of this plugin and upload the new one.
This should solve the error from the link above and give you access to admin panel.