Dear Odoo Programmers,

When you install Odoo V8 and try to confirm Incoming mail server (By cliciking "Test & Confirm" button, you will get following Error.

Connection test failed!

Here is what we got instead:
connect() takes at least 4 arguments (4 given).

Actully this is not Queation, but the this question is itself a solution. See solution as below,

Solution :

To solve this error, You need to put decorator @api.cr_uid_id exactly above connect method,

addons/fetchmail/fetchmail.py and in button_confirm_login method, you will find this problem.

For example,

   @api.cr_uid_id
    def connect(self, cr, uid, server_id, context=None):
        if isinstance(server_id, (list,tuple)):
            server_id = server_id[0]
        server = self.browse(cr, uid, server_id, context)
        if server.type == 'imap':
            if server.is_ssl:
                connection = IMAP4_SSL(server.server, int(server.port))
            else:
                connection = IMAP4(server.server, int(server.port))
            connection.login(server.user, server.password)
        elif server.type == 'pop':
            if server.is_ssl:
                connection = POP3_SSL(server.server, int(server.port))
            else:
                connection = POP3(server.server, int(server.port))
            #TODO: use this to remove only unread messages
            #connection.user("recent:"+server.user)
            connection.user(server.user)
            connection.pass_(server.password)
        return connection

The reason is when you  passing "id" in any method with using New API, you need to use @api.cr_uid_id as decorator in your method. If you don't want to put that decorator then simply pass id in connect method. See Bold fonts on following method.

    def button_confirm_login(self, cr, uid, ids, context=None):
        if context is None:
            context = {}
        for server in self.browse(cr, uid, ids, context=context):
            try:
                connection = server.connect(server.id)
                server.write({'state':'done'})
            except Exception, e:
                _logger.exception("Failed to connect to %s server %s.", server.type, server.name)
                raise osv.except_osv(_("Connection test failed!"), _("Here is what we got instead:\n %s.") % tools.ustr(e))
            finally:
                try:
                    if connection:
                        if server.type == 'imap':
                            connection.close()
                        elif server.type == 'pop':
                            connection.quit()
                except Exception:
                    # ignored, just a consequence of the previous exception
                    pass
        return True

Hope Odoo will modify code soon and solve this problem. :)

Hope this helps,